Individual skill
auditing-cors-policy
Audit a target's CORS posture — Access-Control-Allow-Origin handling, reflected-origin bypass, credentials+wildcard mismatch, preflight OPTIONS behavior, Vary header correctness. Use when: a third-party integration is failing CORS preflight and someone proposes "just set Allow-Origin to *" as the fix, OR your bug-bounty inbox has a credential-reuse exploit chain. Threshold: any reflection of arbitrary Origin into Allow-Origin, Allow-Credentials:true with wildcard origin (browser-rejected combo but server config wrong), missing Vary:Origin on per-origin responses, preflight cached over 86400s, OR Allow-Origin trust of attacker- controlled subdomain pattern. Trigger with: "audit cors", "check cors policy", "cors bypass", "preflight check".
plugins/security/penetration-tester/skills/auditing-cors-policy/SKILL.md
Source commit 0500b275e963c027f6b410e8c49c0446945c574e
What was checked
- Matches the observed repository HEAD
- Yes
- Scanner rules are current
- No
- Repository scan complete
- No
- Skill scan complete
- No
- Observed behavior
- Not checked yet
- Last checked
- Nov 12, 2026
These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.
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Repository context
- Repository stars (not skill ratings)
- 2,917
- Repository last updated
- Nov 12, 2026
- License
- MIT
Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.
- ai Repository topic
- automation Repository topic
- claude-code Repository topic
- devops Repository topic
- mcp Repository topic
- ai-agents Repository topic
- anthropic Repository topic
- claude-code-plugins Repository topic
- developer-tools Repository topic
- llm Repository topic
- security Declared skill tag
- cors Declared skill tag
- web Declared skill tag
- pentest Declared skill tag
- security Derived category
Files and excerpt
File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.
Browse files
SKILL.mdcore · 6,709 bytesSKILL.mdcore · 6,709 bytesSKILL.mdcore · 6,709 bytesSKILL.mdcore · 6,709 bytesreferences/PLAYBOOK.mddoc · 6,216 bytesreferences/THEORY.mddoc · 6,202 bytesscripts/audit_cors.pyruns · 14,802 bytes
Read excerpt
# Auditing CORS Policy
## Overview
CORS misconfiguration is one of the most common middle-severity findings
in web bug bounties. The browser-enforced rules are subtle, the failure
modes are silent (the wrong cors response just works until an attacker
weaponizes it), and the "fix" engineers reach for —
`Access-Control-Allow-Origin: *` — opens the very class of attacks CORS
was meant to prevent when paired with credentials.
This skill probes each common CORS misconfiguration with synthetic
Origin headers and grades the response.