Malformed HTTP messages via newline-tolerant validation
Published Apr 17, 2023 · Updated Feb 5, 2025
Header validation in Slim Framework Slim PSR-7 before 1.6.1 allows remote attackers to create malformed HTTP messages via newline injection. The validateHeaderName and validateHeaderValue methods use PHP regular expressions whose dollar anchors match before a trailing newline, so newline-terminated input passes validation. Exploitation requires an application to pass attacker-controlled header names or values; resulting messages can trigger application errors or cause a remote firewall to block the application's HTTP client.
Summary
What happened
Header validation in Slim Framework Slim PSR-7 before 1.6.1 allows remote attackers to create malformed HTTP messages via newline injection. The validateHeaderName and validateHeaderValue methods use PHP regular expressions whose dollar anchors match before a trailing newline, so newline-terminated input passes validation. Exploitation requires an application to pass attacker-controlled header names or values; resulting messages can trigger application errors or cause a remote firewall to block the application's HTTP client.
The record
- CVE
- CVE-2023-30536
- Published
- Apr 17, 2023
- Updated
- Feb 5, 2025
- Vendor
- Slim Framework
- Product
- Slim PSR-7
- Classifications
- CWE-436, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 17, 2023CVE publishedPublication date reported by the CVE source.
- Feb 5, 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=< 1.6.1
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
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Technologies
Your stack
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Your stack
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