/evidence-hygiene

name: evidence-hygiene
description: "Evidence-capture and PoC-redaction discipline for bug-bounty submissions: cookie redaction protocol (which fields to mask, Preview annotation / Burp panel hiding / DevTools workflow), PII black-bar discipline (what to mask in other-user data — names, emails, phones, faces — vs what is safe to leave — usernames, trace IDs, request bodies), HAR file sanitization (jq filters for Cookie/Set-Cookie/Authorization headers), Burp Repeater/Intruder screenshot hygiene (hide request body, show only Results table for rate-limit attacks), Chrome DevTools Console PoC patterns (credentials include so cookies are not echoed, labeled console.log), screenshot capture order, filename conventions, post-submission rotation hygiene. Use BEFORE any PoC screenshot, BEFORE attaching a HAR, or whenever preparing evidence with session cookies or other-user PII. Pairs with bugcrowd-reporting and report-writing."
sources: community, operator_experience

EVIDENCE HYGIENE — PoC Capture & Redaction Discipline

> Use this skill BEFORE capturing any screenshot, exporting any HAR, or attaching any evidence to a bug-bounty submission. It catches the most common evidence-hygiene mistakes that cause cookies to leak, PII to be shared without consent, or screenshots to be unsuitable for triage.

The core principle: **Bug-bounty evidence is meant to convince a triager. Anything beyond that — live cookies, real-user PII, internal trace IDs that aren't useful — should not be in the evidence.**

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1. Two Categories of Sensitive Data

Every PoC artifact (screenshot, HAR, raw HTTP request, terminal transcript) potentially contains data that needs different treatment.

| Category | Examples | Treatment | |---|---|---| | **Your-account secrets** | Session cookies, OAuth tokens, refresh tokens, API keys | Always redact. Even in private bug-bounty platform attachments. Your account, your session — protect it. | | **Other users' PII** | Real names, emails, phone numbers, addresses, profile photos, account IDs | Redact unless explicitly demonstrating cross-account impact. Even then, mask faces and minimize the data you display. | | **Triager-useful metadata** | Trace IDs (`x-datadog-trace-id`), request IDs, server timestamps, your test account UID/email, GraphQL operation names, response shapes | **Leave visible** — these help the triager correlate to logs and reproduce. | | **Test-account passwords (limited use)** | Throwaway passwords on a test account (e.g., `Testing@5678`) | Acceptable in screenshots if you rotate immediately after submission so the value shown is dead. Don't leave real-use passwords in evidence. |

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2. Cookie Redaction Protocol

2.1 What must be masked

The session cookie value is the highest-value secret in any PoC. Mask:

• The session cookie (`authn`, `session`, `sid`, `__Secure-id`, etc. — name varies per target)
• `csrf-token` if it's bound to your session
• `Authorization` headers (Bearer tokens, JWT)
• `Cookie` request header values for any session-bearing cookie
• `Set-Cookie` response header values for any session-bearing cookie

2.2 What's safe to leave visible

• Cloudflare cookies (`__cf_bm`, `_cfuvid`) — these are bot-management, not session-bearing
• Analytics cookies (`ajs_anonymous_id`, `_ga`)
• Trace correlation IDs (`x-datadog-trace-id`, `x-request-id`)
• Server / framework headers (`Server: cloudflare`, `X-Frame-Options`)
• Your test account email/UID (per Bugcrowdninja alias section in `bugcrowd-reporting`)

2.3 Redaction methods (ranked by practicality)

**Method A — Don't capture the cookies in the first place** (preferred when possible)

• For DevTools Console PoCs: use `credentials: 'include'` so the browser sends cookies automatically. Console output won't echo the cookie. Screenshot the Console output, never the Network tab Headers panel.
• For Burp Repeater PoCs: drag the bottom request/response panel divider DOWN to hide the request body before screenshotting. Capture only the Results table for Intruder runs.

**Method B — Black-bar in image editor** (when capture inevitably includes cookies)

• macOS: Open screenshot in Preview → Tools → Annotate → Rectangle → set fill color to black → drag rectangle over the cookie value → save
• Windows: Use Snip & Sketch's annotation tools or any image editor (Paint.NET, etc.)
• Burp itself: in Burp's Proxy → Match and Replace, you can pre-emptively redact cookie values to placeholder strings before screenshotting

**Method C — Find/replace in raw text** (for HAR files, terminal transcripts)

• See §4 for the jq commands

2.4 Pre-screenshot checklist

Before clicking Capture:

[ ] Network tab Headers panel is collapsed or out of frame
[ ] Burp's Request panel is hidden behind the divider drag
[ ] No "Copy as cURL" output is visible on screen
[ ] DevTools Application → Storage → Cookies tab is closed
[ ] Browser URL bar doesn't show a session token in query string (rare but possible)

After capturing:

[ ] Open the screenshot at full resolution before saving
[ ] Search for the session cookie name substring in any visible text — if present, redact
[ ] Search for the literal first 6 chars of your cookie value — if present, redact
[ ] Compare to the previous PoC screenshot in the same engagement — same redaction discipline

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3. PII Black-Bar Protocol

When a PoC necessarily exposes another user's data (e.g., demonstrating IDOR by showing the victim's email in an attacker-session response), redact the actual PII even in private attachments.

3.1 What to mask (other-user data)

• First name, last name (full or partial)
• Email address (mask the local part; can leave domain if non-identifying)
• Phone number (mask the last 7 digits, optionally leave country code)
• Physical address (mask everything below city)
• Date of birth (mask the year, optionally the month)
• Government IDs (SSN, passport — mask everything)
• Profile photos / face images (black-bar the fa