google/mantis-reproduce
>- Generates and runs crash reproducers to verify security flaws. Use when viable findings exist and you need to write and execute a script or payload to verify the crash. Don't use for code auditing or patching.
npx skills add https://github.com/google/mantis --skill mantis-reproduce
Integration Test Engineer. Designs crash reproducers or inputs and executes them
inside isolated sandbox environments to empirically verify bugs.
/mantis-reproduce [--reattack] [--finding_id=<uuid>] [--force] [--target_root=<path>] [--state_root=<path>] [--snapshot_root=<path>] [--snapshot_id=<SNAPSHOT_ID>] [--snapshot_pinned=<true|false>]
flaws.
--reattack: When executing as part of patch verification to isolatere-attack outcomes.
--finding_id: The specific finding UUID to reproduce. Must be providedand is required when --reattack is specified.
--force: Override/bypass eligibility checks for targeted normal runs.--target_root: Path to the root of the target codebase under test(defaults to .). AUTHORITATIVE when supplied — overrides --snapshot_root
(Block A step 1a); the sentinel check is skipped for this tree (e.g. a
patched shadow during re-attack verification).
--state_root: Path to the root of the Mantis state directory containingworkspace/ (defaults to .).
--snapshot_root: Root of the pinned immutable code snapshot for this pass.Consumed by Block A (Step 0) when --target_root is not supplied.
--snapshot_id: The SNAPSHOT_ID string of the pinned snapshot, consumed byBlock A (sentinel) and Block B (snapshot match check) in Step 0.
--snapshot_pinned: When false (set by mantis-patch during re-attack ona patched shadow), the reproduce sub-agent MUST skip the snapshot
sentinel/match check for this invocation — the --target_root tree is
authoritative and sentinel-exempt (Block A step 1a).
state_root/workspace/findings/ (viable/conditional findings).target_root/ (Repository source files to analyze trigger paths).state_root/workspace/archive/.repro_attempts.json.state_root/workspace/.mantis_state.json (to track current loop pass).poc_[uuid].py or crash_[uuid].payloadinside state_root/workspace/reproducers/).
state_root/workspace/findings/ (sets "repro_status",
"repro_file_path", "run_command", "repro_output", and appends
history). Updates status to "VALID" if provisionally valid.
--reattack: updates findings in-place understate_root/workspace/findings/ (sets "reattack_status",
"reattack_file_path", "reattack_run_command", "reattack_output",
"reattack_variants", and appends history with stage "reattack"). Does
not modify "repro_*" fields or "status". Exception: may atomically
downgrade patch_status per INV-1 in Step 6 (never persist
VERIFIED_SECURE alongside a non-failed_to_bypass reattack_status).
state_root/workspace/archive/.repro_attempts.json atomically."repro_snapshot_id" / "reattack_snapshot_id" on updated findingsand stores .repro_attempts.json values as {count,last_snapshot} objects
(bare integers still read correctly).
state_root/workspace/findings/.state_root/workspace/archive/.repro_attempts.lock file locking and atomic
temporary file swaps (os.replace on
state_root/workspace/archive/.repro_attempts.json.tmp) to guarantee
concurrency safety and retry stability.
matches; refuses to emit a negative verdict without reached-sink evidence.
Re-attack verdicts on a snapshot mismatch are governed by the C5
unpatched-baseline re-run (Step 6), which supersedes the legacy blanket
refusal — a failed_to_bypass verdict is only written after C5 has
confirmed the unpatched baseline still triggers on the current snapshot.
LOCATOR RESOLUTION (before reading ANY target code or artifact):
0. ROLE: If this skill NEVER reads target source (report, calibrate, reflect),
you are a FINDINGS-ONLY stage: skip steps 2-6; still read active_snapshot from
state for provenance/annotation; NEVER stop merely because a code root is unset.
1. Determine CODE_ROOT, in this priority order:
a. If --target_root is passed on THIS invocation, CODE_ROOT = --target_root.
It is AUTHORITATIVE and OVERRIDES SNAPSHOT_ROOT and the state fallback
(used when a caller hands you a prepared tree, e.g. a patched shadow).
b. Else if --snapshot_root (or SNAPSHOT_ROOT) is passed, use it.
c. Else read state_root/workspace/.mantis_state.json (state_root from
--state_root if passed, else ./workspace/... relative to the current dir)
-> active_snapshot.root / .snapshot_id / .snapshot_pinned.
d. Else (no arg AND no readable active_snapshot): CODE_ROOT = current directory,
treat snapshot_pinned = false (MODE-OFF). Do NOT stop.
2. SENTINEL CHECK (only if snapshot_pinned is true AND you did NOT take path 1a):
verify CODE_ROOT/.mantis_snapshot_id exists and equals SNAPSHOT_ID. If missing
or different -> STOP "snapshot sentinel mismatch". (A --target_root tree (1a) is
deliberately mutated and is sentinel-EXEMPT.)
3. PATH FIELDS:
- SNAPSHOT-RELATIVE (read under CODE_ROOT): code_paths entries; plan target_files
that are file paths. Strip ONLY a trailing ":<digits>". A code_paths entry
containing "://" is a URL/endpoint, NOT a file read. A code_paths entry that is
NOT of the form <existing-path>:<integer> is a non-source LOCATOR
(symbol/offset/endpoint): only check that the artifact/symbol exists; skip ALL
line-range and line-existence logic.
- STATE-RELATIVE (read/write under state_root/workspace, NEVER prefix CODE_ROOT):
kb_references, repro_file_path, reattack_file_path, helper scripts, report
files, and all state/findings JSON.
4. Never WRITE under CODE_ROOT when snapshot_pinned is true. Any command that
compiles, generates, or writes artifacts MUST run in a PRIVATE SHADOW copy
(mktemp -d from CODE_ROOT), never with cwd=CODE_ROOT. Read-only inspection may
cd into CODE_ROOT.
5. VCS-METADATA CARVE-OUT: history-log extraction and any VCS diff/blame command
run in the LIVE repository root (which still has .git/.hg/.repo), NOT CODE_ROOT
(the snapshot copy strips VCS metadata). Do NOT stop merely because CODE_ROOT
lacks .git/.hg/.repo.
6. Every shell command uses ABSOLUTE paths and sets its own working directory on
that call. Do NOT assume the working directory persists between calls.
> [!NOTE] **CURRENT-PASS CHECK (defensive; the binding guarantee is on the
> harness per mantis-pipeline-adapter Scenario 2):** if active_snapshot is
> present AND active_snapshot.pass != state.pass_number, treat the snapshot as
> STALE for this pass — STOP "stale active_snapshot: pass mismatch" or degrade
> as HALT (snapshot_pinned effectively false: no authoritative verdicts, Block
> B NOT_MATCHED, reproduce not_attempted). This catches a custom harness that
> preserved active_snapshot across the Stage 15 pass increment without
> re-pinning. The reference meta-agent re-pins every pass, so this check never
> fires there. Block B itself cannot detect this (it is snapshot_id-only, not
> pass-aware).
SNAPSHOT MATCH CHECK for finding F (decides MATCHED vs NOT_MATCHED):
1. If snapshot_pinned is false -> NOT_MATCHED. Stop.
2. Read F.discovery_commit:
- missing OR empty OR the literal "MIXED" -> NOT_MATCHED.
- not exactly equal to SNAPSHOT_ID -> NOT_MATCHED.
- exactly equal to SNAPSHOT_ID -> MATCHED.
There is no other route to MATCHED; never fuzzy-compare. The global "default the
field and proceed" backward-compat rule does NOT apply to discovery_commit:
absent = NOT_MATCHED. (There is NO separate "dirty" gate: a dirty tree's
SNAPSHOT_ID already embeds the working-tree content hash, so within-pass findings
MATCH and cross-pass bare-commit findings do not.)
Notes: When invoked by the patcher with --target_root=<shadow> (a patched
copy), Block A step 1a makes that shadow the authoritative CODE_ROOT and SKIPS
the sentinel check (the shadow is deliberately mutated). Otherwise CODE_ROOT is
the pinned snapshot and the sentinel MUST match. Stamp repro_snapshot_id
(normal run) or reattack_snapshot_id (--reattack) = the current SNAPSHOT_ID
(from --snapshot_id or state active_snapshot.snapshot_id) on every finding
you update.
Write a Proof-of-Concept Reproduction Script (Repro) or raw input payload file
that reproduces a confirmed security flaw.
Execute the reproduction stage under these constraints:
--finding_id is supplied:(state_root/workspace/findings/<uuid>.json). Exit if it does not exist.
--reattack is specified: Enforce the **expected patch workflowstate** for the loaded finding:
"status" must be "VALID" or "PROVISIONALLY_VALID"."repro_status" must be "reproduced"."patch_status" must NOT be "MITIGATION_PROPOSED".(VERIFIED_SECURE IS allowed: C5 below atomically downgrades it when
the re-attack outcome is not failed_to_bypass.)
invalid state.
--reattack is NOT specified (Targeted Normal Run):--force is NOT specified, enforce standard eligibility filters:"status" must be "VALID" or"PROVISIONALLY_VALID".
"production_viability" must be "VIABLE","SAMPLE_OR_TEST", or "CONDITIONAL_VIABLE".
invalid state.
--force is specified, bypass these eligibility checks.--finding_id is not supplied:--reattack is specified (it requires--finding_id).
state_root/workspace/findings/ directory."status" is "VALID" or "PROVISIONALLY_VALID"."production_viability" is "VIABLE", "SAMPLE_OR_TEST", or"CONDITIONAL_VIABLE" (or skip this viability filter if not checking
viability, but always check status).
Tier 0 — Structural Reachability Pre-Check (Advisory Queue Sorting): If a
structural code index (mantis-structural-index) is available, you MAY query
query_structural_index.py (find_callers) before authoring code to check
whether an AST call path exists from a public entrypoint to the vulnerable
sink. Use this query to prioritize candidate execution order (process
findings with verified AST reachability first).
Call graphs miss macros, function pointers, dynamic dispatch, and interface
tables. An absent call path MUST NEVER reject a finding, skip reproduction,
or set failed_to_reproduce.
Snapshot drift check: For each loaded finding, if it already has a
repro_snapshot_id and Block B (Step 0) returns NOT_MATCHED, treat any
stored PoC/offsets as STALE: regenerate the reproducer from scratch against
the current CODE_ROOT (do not reuse old line numbers/addresses). If Block B
is MATCHED you may reuse an existing PoC.
on your parent host terminal using terminal/shell execution tools.
sandbox execution tools provided by your environment. For memory-safety
PoCs, restrict network access and file system writes as much as possible.
For logic/auth functional tests, you may enable local network services as
needed, but never expose the environment to the external internet.
(e.g., poc_[uuid].py or a C reproducer file in the same directory) or write
a raw crash input data payload (e.g., crash_[uuid].payload) that triggers
the target bug. **All generated PoC/re-attack scripts and payloads MUST be
written inside the state_root/workspace/reproducers/ directory (never in
the target_root directory).** You must ensure the parent directory
state_root/workspace/reproducers/ exists (e.g. using mkdir -p) before
writing any files. Analyze the code path and constraints carefully. If your
initial reproduction attempt fails, evaluate if the finding details (such as
input paths, parameters, or assumptions) are slightly incorrect based on your
observations, and adjust the finding details dynamically to attempt a fix. If
you cannot find a triggerable path after trying multiple approaches and
adjustments, abandon the attempt. **Do NOT directly mark it as
failed_to_reproduce** — route the abandon decision through the Step-5 Block
F (Reached-Sink Evidence) gate: if the harness provably reached the
vulnerable entrypoint but the bug did not fire, classify as
failed_to_reproduce; if evidence is absent (setup/build failure, exit 127,
"No such file", or the sink was never reached), classify as not_attempted
(retry-eligible). A raw negative from a setup/build failure burns the retry
cap and silently drops a real bug.
To run your script or payload, use the execution or containerization tools
available in your environment to execute the code safely. Select the most
appropriate runtime image and flags for the target. **All compilation and
test execution commands MUST be run in a PRIVATE BUILD SHADOW, never with
Cwd=CODE_ROOT (the snapshot is read-only — Block A step 4).** Before
compiling, create BUILD_ROOT=$(mktemp -d) and copy CODE_ROOT into it (e.g.
cp -a CODE_ROOT/. BUILD_ROOT/); run all compilation/test commands with
Cwd=BUILD_ROOT; delete BUILD_ROOT on teardown. Keep the generated PoC file
itself under state_root/workspace/reproducers/ (STATE-RELATIVE) and store
its ABSOLUTE path in "run_command"/"reattack_run_command".
Sanitizer compilation (C/C++ targets): When the bug class is
memory-safety or undefined-behavior, compile with
-fsanitize=address,undefined (ASan + UBSan) at a minimum. For data races,
add -fsanitize=thread (TSan) — TSan is also mutually exclusive with ASan,
so use a separate build. Use -fno-omit-frame-pointer for usable stack
traces. These flags surface bugs that would otherwise exit 0 silently (UBSan
defaults to recover-mode). MSan caveat: MemorySanitizer
(-fsanitize=memory) detects uninitialized-memory reads, but it requires the
ENTIRE dependency chain (including libc and the C++ runtime) to be
MSan-instrumented — on an arbitrary target that is usually not the case, so a
naive -fsanitize=memory build yields bogus WARNING: MemorySanitizer
traces. MSan is also mutually exclusive with ASan in one build (use a
separate build, not an additive flag). If a fully instrumented MSan
environment cannot be guaranteed, do NOT add -fsanitize=memory; fall back
to ASan+UBSan rather than trusting a possibly-bogus MSan trace. Recognizing
MSan output as evidence (Step 5) is still correct when a legitimate MSan
instrumented build is available. Sanitizer consistency guardrail: the
SAME sanitizer flags MUST be used for the baseline, attack, and re-attack
runs — a different sanitizer can mask the bug and produce a false negative
(INV-2) or false VERIFIED_SECURE (INV-1). See Block G.
{TARGET_ROOT} token substitution (numbered step):
run_command or reattack_run_command, use the literaltoken {TARGET_ROOT} for any path that references the target tree.
{TARGET_ROOT} with the actual root:CODE_ROOT (the snapshot or --target_root).CODE_ROOT /--target_root / active_snapshot.root.
never bake an absolute .mantis_snapshots/pass_<N> path into the stored
command.
Execute your reproduction using the appropriate environment: If the
target is firmware, you may write a script to boot it via qemu, unicorn,
or Firmadyne. If it's a binary, you may use dynamic instrumentation or
standard execution. Use your best judgment to construct a working harness for
the artifact.
available, deploy concurrent workers taking diverse logical approaches to
reproduce the bug. If any trajectory succeeds, immediately adopt its
payload and discard the others to escape potential "give up" loops and
prune compute costs.
trajectory worker (or a single agent) uses a tiered escalation ladder
(Tier 1 -> Tier 2 -> Tier 3) to refine its trigger payload incrementally
rather than attempting a single-shot end-to-end launch.
lightweight test calling the vulnerable function/module directly to
verify that the core bug hypothesis is sound in isolation.
input serialization, parsers, routing, and auth wrappers to verify the
input survives intermediate processing without sanitization or
truncation.
self-contained PoC against the target service via public APIs inside the
isolated sandbox (Docker, QEMU, VM). Yields the authoritative
reproduced verdict per Block F.
record repro_status = "reproduced" or "statically_confirmed" based on
a Tier-1 or Tier-2 execution.
that feeds a private/static function or bypasses the public API (Step 4),
and the payload cannot be escalated to trigger through Tier 3 (the public
API / sandboxed service), you MUST TERMINATE AND RECORD
repro_status = "failed_to_reproduce" with details citing
"Internal Invariant Protection".
trial runs are bounded local execution steps (max 3 trial executions per
conversation) and DO NOT increment the absolute per-finding attempt
counter in state_root/workspace/archive/.repro_attempts.json.
executions (or full end-to-end reproducer runs) increment the absolute
attempt counter toward the hard ceiling of 6 (Section 6).
payload parameters, fix harness setup, and retry up to 2-3 times within
the active conversation before reporting back to the orchestrator.
When invoked with --reattack, you MUST author and execute **N ≥ 3
boundary-mutated variant inputs** in addition to re-running the original PoC.
The schema (schema.json) literally calls this the "variant-hunting re-attack"
— merely re-running the original PoC is insufficient. Over-narrow patches that
guard the exact PoC bytes are the dominant auto-repair failure mode; variant
hunting is the zero-infra-cost defense against them.
Legacy findings: Findings with absent reattack_variants (created before
this rule existed) are re-verified under the ≥3 variant requirement on their
first --reattack pass. This is intentional — legacy VERIFIED_SECURE verdicts
are upgraded to the stricter gate — but expect one-time churn across archived
findings on the first pass that runs variant hunting.
What to generate (bug-class-aware):
overflow):** Author at least 3 of:
len = bound, len = bound + 1, len = bound - 1.len ± 1, len = 0, len = SIZE_MAX, sign flips onsigned lengths.
multiple call sites, author a variant reaching it through a different path
(e.g., different API endpoint, file format variant, or protocol command).
same sink.
Hunt for actual variants of the same class:
/api/v2/echo when PoC targets/api/v1/echo, or alternate parameter names.
..%2fetc%2fpasswd, ..\\..\\, URL-encoding,double encoding, unicode normalization variants.
privilege-escalation paths.
'; EXEC--, UNION SELECT, blind variants,alternate injection points.
subagents to author and test variants in parallel. Each subagent gets one
mutation strategy, writes its variant PoC, and reports whether it triggered.
Aggregate all results before setting reattack_status. If subagents are
unavailable, do them sequentially.
Execution: Write each variant as a separate script in
state_root/workspace/reproducers/ (e.g., reattack_variant_[uuid]_[N].py).
Execute each against the patched shadow (--target_root) using the same
isolation constraints as Step 3. Record each variant in the reattack_variants
array using EXACTLY the schema keys
{"description": "...", "triggered": true/false} (Step 6).
Verdict rule: reattack_status = "failed_to_bypass" requires a non-empty
reattack_variants array containing ≥ 3 valid variant inputs that ALL failed to
trigger the bug on the patched shadow. An empty or short set makes "all variants
failed" vacuously true — this is FORBIDDEN: if fewer than 3 meaningful variants
can be constructed after genuine effort, cap at VERIFICATION_INCOMPLETE
(history note insufficient_variants), NEVER failed_to_bypass. The [] case
may ONLY coexist with a non-failed_to_bypass status (e.g., C5 baseline failure
that halted before variant hunting).
Variant validity guardrail: A variant counts as a bypass (triggered = true
causing bypassed_patch) ONLY if it satisfies BOTH:
same sink function / sanitizer signature / crash type. A junk mutant (e.g.,
len=SIZE_MAX causing an unrelated OOM, an alternate endpoint 404-ing then
erroring, or a completely different crash) does NOT count as a bypass.
Discard it (set triggered = false with a description noting it was invalid)
and continue. For non-memory bugs (logic, auth, injection), compare the same
sink function or behavior (e.g., same unauthorized action succeeds, same
injection executes, reaches the same sink function) — NOT a ±line window
against a pre-patch line number (patches shift lines, and non-memory bugs
often have no precise sink line). If you cannot positively confirm a
triggering variant is a DIFFERENT bug, count it as a bypass (fail-closed:
prefer a false VERIFICATION_FAILED over a false VERIFIED_SECURE).
public API or internal invariants — it must not rely on artificial harness
tricks (e.g., private-function direct calls with custom-allocated buffers)
that bypass the library's execution invariants.
Ideally, confirm each triggering variant still triggers on the unpatched
shadow (same baseline the original PoC ran against) to prove it exercises the
original bug rather than an artifact. If the unpatched shadow is unavailable
(e.g., snapshot mismatch), require the same-sink evidence (same sanitizer frame,
same crash address, same logic failure) as corroboration.
If ANY valid variant triggers the bug, set reattack_status = "bypassed_patch"
and apply INV-1 (downgrade VERIFIED_SECURE → VERIFICATION_FAILED).
reproduced: The PoC successfully triggered the vulnerability.failed_to_reproduce: The PoC was executed but did not trigger thevulnerability.
statically_confirmed: Reproduction was impossible due to environmentalconstraints (e.g., missing hardware emulators, unavailable external
services) but the flaw is statically obvious (e.g., hardcoded credentials).
This is strongly discouraged and should only be used as a last resort.
not_attempted: The reproduction stage was skipped entirely (e.g., dueto infrastructure setup failure, timeouts, or explicit skip configuration).
public-facing APIs wherever possible, or strictly respect the library's
global execution invariants (such as allocator padding) to avoid generating
artificial, non-viable crashes.
by compiling a direct-call harness that feeds a private/static function a
custom-allocated buffer (e.g., malloc(15)) that bypasses the library's
guaranteed allocator wrappers (e.g., png_malloc(rowbytes + 48)).
allocation padding, classify the finding as "failed_to_reproduce" due to
"Internal Invariant Protection."
stderr, and exit codes to classify reproduction success depending on the bug
class:
Before classifying ANY negative outcome (failed_to_reproduce, or in
--reattack mode failed_to_bypass), apply this gate:
REACHED-SINK EVIDENCE GATE (mechanical):
Each reproducer produces REACHED-SINK EVIDENCE via ONE channel, recorded in repro_hints:
(a) script/source harness -> write the exact bytes MANTIS_REACHED_ENTRYPOINT to a
sidecar file $SENTINEL_FILE and flush+fsync (or unbuffered write) BEFORE
invoking the sink. (A file survives a crash that truncates buffered stdout.)
(b) binary / firmware / raw-payload -> reached-sink evidence is a captured
crash backtrace or sanitizer frame (ASan/UBSan/MSan/TSan) that
explicitly names the target sink function (target-produced tracing). A
marker written by a wrapper you author BEFORE invoking the target is
SETUP EVIDENCE ONLY: it proves "launch attempted," not "sink reached,"
and does NOT qualify as reached-sink evidence. If no in-path marker
(channel a) and no target-produced backtrace/sanitizer trace
(channel b) is achievable, the sink is unreached.
EVIDENCE PRESENT (reached-sink) = (channel a) sidecar file contains
MANTIS_REACHED_ENTRYPOINT written in-path, OR (channel b) target-produced
backtrace/sanitizer output names the sink. A wrapper pre-launch marker alone is
NOT evidence present.
EVIDENCE ABSENT includes: any compiler/build nonzero exit; exit 127 (command not
found); exit 2 with a "No such file" message.
DECISION GATE (gate the DECISION, not specific verdict strings):
- Record repro_status = reproduced OR statically_confirmed ONLY if EVIDENCE is
PRESENT. If ABSENT -> repro_status = not_attempted (retry-eligible), STOP.
- In patch verification, EVIDENCE is required on the UNPATCHED baseline (Block G),
NOT on the post-patch attack run (a correct patch legitimately stops the input
before the sink).
- If NO evidence channel is achievable for this target, downgrade to
not_attempted / VERIFICATION_INCOMPLETE. NEVER synthesize the marker.
Concretely: if the run produced NO reached-sink evidence (build/setup error,
exit 127, "No such file", or the sink was never reached), record
repro_status = not_attempted (retry-eligible) — NEVER
failed_to_reproduce; and in --reattack mode leave reattack_status UNSET
with a history note "setup_failed" — NEVER failed_to_bypass. Only classify
a negative when the harness provably reached the vulnerable entrypoint and
the bug did not fire.
HALT ceiling (3-state rule): If active_snapshot is present in state but
snapshot_pinned is false (HALT mode — the tree raced or could not be
pinned), you MUST NOT record failed_to_reproduce or failed_to_bypass at
all. In HALT, the code may have drifted and a negative reproduction result
cannot be trusted as authoritative. Instead, record
repro_status = not_attempted (retry-eligible) and, in --reattack mode,
leave reattack_status UNSET with a history note "HALT mode: snapshot
unpinned, negative result suppressed". This mirrors the authoritative-verdict
prohibition that applies to all stages in HALT. (In MODE-OFF — no
active_snapshot — classify negatives normally as today.)
unit test or script that explicitly demonstrates the logic failure (e.g.,
an unauthorized request returns 200 OK, or a test script successfully
bypasses validation and exits with 0).
crash signal or sanitizer trace in stdout/stderr, mark the reproduction as
"reproduced". **Scan stdout/stderr for sanitizer signatures regardless of
exit code** — UBSan defaults to recover-mode (exit 0), so an exit-0 run can
still contain a valid UBSan trace proving the bug fired. Check for:
ERROR: AddressSanitizer).runtime error:, SUMMARY: UndefinedBehaviorSanitizer).
WARNING: MemorySanitizer).**MSan evidence is valid ONLY if repro_hints records that a
fully-instrumented MSan build was available** (Step 3 caveat). A naive
-fsanitize=memory build without full instrumentation produces bogus
traces — do NOT classify these as "reproduced".
WARNING: ThreadSanitizer).139).134).re-emit or manually rewrite the entire JSON object in your output.** Instead,
use in-place editing tools (like a short script in your preferred language,
or jq) to programmatically append the new fields to the existing
state_root/workspace/findings/<id>.json file.
Additionally, you must Update the Reproduction Attempt Cache to help the
planner track attempts efficiently:
state_root/workspace/archive/.repro_attempts.json. Ensure the parent
directory state_root/workspace/archive/ exists (e.g.,
mkdir -p state_root/workspace/archive/) before creating, reading, or
locking the cache file.
UUIDs are regenerated. If the finding has a signature field, use it
directly as the cache key (it is already a deterministic content-identity
hash). If signature is absent, fall back to a computed stable key using
the finding's normalized title and its primary file path:
stable_key = normalized_title + "@" + primary_file_path.
normalized_title by converting the title to lowercase andremoving all non-alphanumeric characters.
primary_file_path by taking the first entry in code_paths andstripping any line number suffixes (e.g., converting src/auth.c:120 to
src/auth.c).
{count, last_snapshot}): store eachcache value as an object {count, last_snapshot}. When reading a value
V: if V is a bare integer, treat count=V and last_snapshot=UNKNOWN; if V
is an object, use V.count / V.last_snapshot (default UNKNOWN). Before
incrementing, run Block B comparing the finding's snapshot to the current
SNAPSHOT_ID: reset count=0 ONLY when Block B is NOT_MATCHED *because
the two snapshots are present and actually differ* (a genuine code change
earns a fresh budget). Do NOT reset on UNKNOWN (absent/pass_/unpinned)
— that would make no-VCS targets retry forever. Additionally keep an
absolute per-finding-id attempt counter that is NEVER reset, and stop
retrying once it reaches a hard ceiling (e.g. 6) regardless of snapshot
changes.
bypasses caused by atomic file replacement) and protect lockless readers:
state_root/workspace/archive/.repro_attempts.lock which is never
deleted or replaced.
fcntl.flock on this lockfile:
state_root/workspace/archive/.repro_attempts.lock(creating it if missing) and acquire an exclusive lock (fcntl.flock
with fcntl.LOCK_EX) inside a context manager (with statement).
state_root/workspace/archive/.repro_attempts.json (treating it as {}
if missing or empty).
count field of this finding's cache-key entry — keyed bysignature if present, else stable_key, the SAME key selection defined
above (the {count, last_snapshot} object) — by 1 ONLY for Tier-3 (full
end-to-end sandboxed service) executions. Internal Tier-1 and Tier-2
stepping-stone trials MUST NOT increment count (they are governed by
the sub-budget rule in Step 3).
state_root/workspace/archive/.repro_attempts.json.tmp).
os.replace in Python) to ensure readers never see a truncated or
incomplete file.
by exiting the with context manager).
Depending on whether the --reattack flag is provided:
--reattack flag): You must append or update thefollowing on the existing object:
"repro_status" ("reproduced", "statically_confirmed","not_attempted", or "failed_to_reproduce").
"repro_file_path""run_command""repro_output""repro_snapshot_id": the current SNAPSHOT_ID this run executed against."repro_hints": Record compilation and sandbox execution telemetry(e.g., sanitizers_used: ASan+UBSan, assertions_disabled: true,
build_profile: release) to provide empirical execution evidence for
/mantis-critic.
repro_status is evaluated as "reproduced"or "statically_confirmed") and the finding's current "status" is
"PROVISIONALLY_VALID": BEFORE upgrading, scan the finding's
triage_checklist (if present). If ANY entry has outcome == "UNKNOWN"
(or passes == false), do NOT upgrade: leave status as
"PROVISIONALLY_VALID", still set repro_status to the success value
(reproduction DID succeed), and append a history note
upgrade-to-VALID-blocked: triage_checklist has UNKNOWN entries (re-review required).
This avoids violating the schema's VALID ⇒ no UNKNOWN allOf gate
(schema.json lines 471-507), which forbids UNKNOWN/passes:false on
any VALID non-chain finding's triage_checklist. Reproduce does NOT
touch triage_checklist entries (the checklist is review's artifact;
only review may resolve UNKNOWN entries). If triage_checklist is
absent (no reviewer history entry, e.g. a legacy finding), or NO entry
is UNKNOWN/passes:false, you must update "status" to "VALID".
"history" array: {
"stage": "reproduce",
"action": "reproduced",
"details": "Reproduction status evaluated as [reproduced/failed_to_reproduce] using command: [run_command]",
"pass_number": <current_pass_number>,
"timestamp": "<current_iso8601_timestamp>"
}
--reattack: You must append or update the following onthe existing object (do not touch repro_* or status):
"reattack_status" ("bypassed_patch", "failed_to_bypass","inconclusive_baseline_changed").
"bypassed_patch": The PoC bypassed the patch and triggered the bug. Ifpatch_status is VERIFIED_SECURE, atomically set
patch_status = "VERIFICATION_FAILED" in the same write (a bypass
defeats the patch). This is an explicit exception to "do not touch
status" and applies to both the C5 step-3 path and same-snapshot runs.
"failed_to_bypass": The PoC was run but failed to bypass the patch. (Nodowngrade needed — failed_to_bypass is the value the allOf gate
requires for VERIFIED_SECURE.)
"inconclusive_baseline_changed": The unpatched baseline was re-run (seeC5 below) and the bug NO LONGER TRIGGERS on the current unpatched code.
Do NOT claim failed_to_bypass. If patch_status is VERIFIED_SECURE,
atomically set patch_status = "VERIFICATION_INCOMPLETE" in the same
write.
VERIFIED_SECURE allOf gate):VERIFIED_SECURE => reattack_status must be failed_to_bypass, and
failed_to_bypass requires a non-empty reattack_variants array with ≥
3 valid variant inputs (Step 3a) that ALL failed to trigger the bug on
the patched shadow. An empty or short variant set makes "all failed"
vacuously true — this is FORBIDDEN: cap at VERIFICATION_INCOMPLETE
instead. Any other outcome MUST atomically downgrade patch_status in
the same write — VERIFICATION_INCOMPLETE for
inconclusive_baseline_changed or an insufficient variant set,
VERIFICATION_FAILED for bypassed_patch. Never persist
VERIFIED_SECURE alongside a non-failed_to_bypass reattack_status.
reattack_snapshot_id != repro_snapshot_id, do NOT independently
record a verdict — follow C5, which re-establishes the unpatched baseline
on the CURRENT snapshot. If C5 cannot run, fall back to leaving
reattack_status UNSET with a SNAPSHOT_MISMATCH history note.
on the patched build, if reattack_snapshot_id != repro_snapshot_id (a
genuine snapshot change, NOT a HALT-mode live: tree), FIRST
re-establish the unpatched baseline:
snapshot — a fresh mktemp -d copy of active_snapshot.root, NOT the
patched shadow. (This is the same unpatched baseline that
mantis-patch Block G step 1 runs; reproduce has no Block G.)
F): set reattack_status = "inconclusive_baseline_changed", do NOT
proceed with the attack, do NOT claim failed_to_bypass. You MUST
still populate reattack_file_path, reattack_run_command, and
reattack_output with the baseline re-run's details. Apply INV-1
(downgrade VERIFIED_SECURE -> VERIFICATION_INCOMPLETE).
(bypassed_patch or failed_to_bypass). Apply INV-1 (downgrade
VERIFIED_SECURE -> VERIFICATION_FAILED if bypassed_patch).
MUST use the same sanitizer flags that made the original baseline
trigger. If the baseline triggered via UBSan (exit 0), recompiling the
attack without UBSan would mask the bug and produce a false negative
(INV-2) or false failed_to_bypass (INV-1).
(active_snapshot.snapshot_id starts with live:), NOT the
--snapshot_pinned=false argument (that's only the sentinel-exemption
for the patched shadow). In HALT, skip C5 and follow the existing HALT
ceiling (leave reattack_status UNSET with the HALT note).
the unpatched baseline to trigger.
"reattack_file_path""reattack_run_command""reattack_output""reattack_variants": An array of objects, one per variant inputattempted during Step 3a. Each object MUST contain EXACTLY the two
required keys "description" (string) and "triggered" (boolean). Do
NOT invent free-form or custom keys (such as input, result,
bypassed, label, name):
"reattack_variants": [
{
"description": "off-by-one: len=bound+1",
"triggered": false
},
{
"description": "alternate path via /api/v2/echo",
"triggered": false
},
{
"description": "boundary mutation: max INT_MAX",
"triggered": false
}
]
"description": What the variant does (e.g.,"off-by-one: len=bound+1", "alternate path via /api/v2/echo").
"triggered": boolean — whether this variant triggered the originalvulnerability class on the patched shadow (per the variant validity
guardrail in Step 3a). Invalid/junk mutants that produced an unrelated
crash or error are recorded as triggered = false with a description
noting invalidity. reattack_variants MUST be non-empty (≥ 3 entries)
for reattack_status = "failed_to_bypass". An empty array [] may
ONLY coexist with a non-failed_to_bypass status (e.g., C5 baseline
failure that halted before variant hunting, or
inconclusive_baseline_changed).
"reattack_snapshot_id": the current SNAPSHOT_ID this run executedagainst.
"history" array: {
"stage": "reattack",
"action": "reproduced",
"details": "Re-attack status evaluated as [bypassed_patch/failed_to_bypass] using command: [reattack_run_command]",
"pass_number": <current_pass_number>,
"timestamp": "<current_iso8601_timestamp>"
}
example of reproducing the reported vulnerability, have a subagent with a
fresh context window review and criticize the generated PoC. Seek genuine
criticism to ensure false reports are never surfaced later.
Variant criticism (re-attack only): When --reattack is specified, the
critic subagent MUST also verify that the variant inputs (Step 3a) are
genuinely diverse — not trivially identical mutations (e.g., changing a
comment while keeping the same payload). If the critic finds the variants are
not meaningfully diverse, record a history note
variant_diversity_insufficient and re-author variants before finalizing
reattack_status.
When complete, notify the user.
Take google/mantis-reproduce from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.