Script source disclosure via ignored filter errors
Published Aug 5, 2025 · Updated Nov 3, 2025
Unchecked return-value handling in ModSecurity 2.9.11 and earlier allows remote attackers to disclose script source or enable XSS. In hook_request_late in mod_security2.c, mod_security2 ignores AP_FILTER_ERROR from request-body reading and continues processing, causing duplicate HTTP responses. Exploitation requires Apache with mod_security2 enabled and a request that triggers the filter error; the resulting error response can override Content-Type.
Summary
What happened
Unchecked return-value handling in ModSecurity 2.9.11 and earlier allows remote attackers to disclose script source or enable XSS. In hook_request_late in mod_security2.c, mod_security2 ignores AP_FILTER_ERROR from request-body reading and continues processing, causing duplicate HTTP responses. Exploitation requires Apache with mod_security2 enabled and a request that triggers the filter error; the resulting error response can override Content-Type.
The record
- CVE
- CVE-2025-54571
- Published
- Aug 5, 2025
- Updated
- Nov 3, 2025
- Vendor
- OWASP ModSecurity
- Product
- ModSecurity
- Classifications
- CWE-252, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 5, 2025CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 2.9.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
- Malformed chunked request proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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