triaging-security-reports

name	triaging-security-reports
description	Use when a vulnerability or security report arrives for triage, when assessing a CVE/RCE/OGNL/injection claim against the code, or when drafting a reply to a security researcher — to research the claim from source without trusting the reporter and without fabricating your own facts.

Triaging Security Reports

Overview

A security report is a claim to be tested, not a finding to be confirmed or rebutted. The reporter may be right, wrong, partially right, or right about the symptom and wrong about the cause. Your job is to independently re-derive the truth from current source.

Core principle: Every factual statement that ends up in your assessment or reply — the reporter's claims and your own — must be traced to current source code before you write it down. The most common failure is not believing the reporter; it is inventing supporting facts to justify a verdict you already reached.

Process authority: SECURITY.md is the source of truth for the disclosure process (private handling, assessment checklist, reporting rules). Read it. This skill governs how you research and respond, not the process itself.

The Iron Rule

NO CLAIM IN A SECURITY RESPONSE WITHOUT A FILE:LINE YOU READ THIS SESSION.

Applies to the verdict, every mitigation you cite, and every "default" you state. If you can't point to the line, you can't write the sentence.

Research: report-blind, not report-led

Read the report once to know what to investigate. Then research as if you were auditing that area cold — do not let the report's framing drive your search.

For each claim, independently verify:

Reporter asserts	You must verify from source
A line number ("bug is at X:392")	Read that line and its call path — is it even reachable as described?
A severity / CVSS	Re-derive from actual exploitability, not their number
"No mitigation / no gate exists"	Search for gates, filters, allowlists, authorizers yourself — absence claims are the most often wrong
"Default configuration"	Check the effective runtime default, not one source (see trap below)
"Same as CVE-XXXX"	Confirm the mechanism actually matches; analogy ≠ equivalence
A working PoC	Run it if it is runnable, then trace whether the payload survives every filter on the path

If the report has no reproducible PoC against a default config, that is itself a triage outcome — say so per SECURITY.md.

Find the control case

A single odd behaviour is ambiguous — it can nearly always be read as intended. What settles it is the sibling that behaves correctly under the same input.

Before writing a verdict, find the case that ought to differ and check it: the annotated property beside the unannotated one, the ordinary setter beside the dynamic one, the sibling path the same control does cover. Behave alike and you are probably looking at a design decision. Diverge, and the control is incomplete — that divergence is the finding.

Prefer an executed differential to an argued one. An existing test that passes beside the reporter's failing one is the strongest evidence a triage can produce.

The effective-default trap

A Java field initializer and the shipped config can disagree. Reading only one produces a confident, wrong claim.

private boolean requireAnnotations = false;   // field initializer

struts.parameters.requireAnnotations=true     # default.properties OVERRIDES it

The effective default is true. Always trace the full chain: field initializer → @Inject setter → default.properties → any struts.xml override. State the effective runtime value, and cite the file that actually wins.

Vulnerability vs. operator responsibility

"In the default configuration" is a crutch — drop it. Decide the real question:

• Is it a vulnerability? Then it's a vulnerability whether or not it's the default. Handle it privately per SECURITY.md.
• Does it require an operator to opt into an insecure configuration? A documented, opt-in setting (e.g. cookiesName=*, devMode=true) that works as advertised is the operator's responsibility, provided the docs carry the warning. Say "X works as documented; the operator owns the security implications of enabling it" — not "not a vuln in the default config."
• Is the RCE/escalation only reachable via application code the framework can't constrain? (e.g. an action that moves an uploaded file to a web root.) Then it's an application concern, not a framework vulnerability — state that boundary explicitly.

Drafting the reply

• Lead with the verdict and the reason, both grounded in file:line.
• Cite a source for every mitigation you mention. If you didn't verify it this session, delete the sentence.
• Prefer "works as documented / operator responsibility" framing over "default configuration."
• Don't over-promise. Before pledging a hardening change, check it doesn't already exist (it often does) and that you intend to actually do it.
• Acknowledge anything the reporter got right (e.g. correct CVE-fix verification) — it builds the relationship and signals you actually read it.
• Keep it private: no public issue, PR, Jira, or list thread before triage. Never open a PR that is itself the security fix (see CLAUDE.md).

Red Flags — STOP

• About to write "this is mitigated by X" — did you read X's line this session?
• About to state a "default" from a field initializer — did you check default.properties?
• Citing the reporter's line number without having traced its call path.
• Asserting "no gate / no check exists" without having grepped for it.
• Two of your own claims contradict each other → at least one is unverified. Stop and verify both.
• Promising a fix/warning "we'll add" without checking it isn't already there.
• Writing "not a vulnerability in the default configuration" → reframe as vuln-or-not + operator responsibility.

Common Mistakes

Mistake	Reality
"Reporter cited line 392, so that's the bug site"	A line is only a bug if it's reachable as described. Trace callers.
"The field defaults to false, so the gate is off by default"	default.properties may override it to true. Check the effective value.
"I'll add a mitigation to strengthen the rejection"	An unverified mitigation that's wrong discredits the whole response. Verify or omit.
"It rejects the payload, obviously"	Confirm the specific PoC string fails the specific filter (e.g. full-match regex ACCEPTED_PATTERN).
"We should add a startup warning"	Grep first — the warning frequently already exists.
"Not a vuln in default config"	Either it's a vuln or it's operator-owned opt-in. The default-config hedge muddies both.