Cross-user request disclosure via stale input buffer
Published Jan 19, 2024 · Updated Nov 3, 2025
Information disclosure in Apache Tomcat 8.5.7 through 8.5.63 and 9.0.0-M11 through 9.0.43 allows remote attackers to read request data. Http11InputBuffer.fill leaves its ByteBuffer limit and position inconsistent when a socket read fails, so later request parsing can place residual bytes from another request in the default error response. Exploitation requires an incomplete POST to a request-body-reading application and timing with another user's request; the disclosed consequence is cross-user request-body exposure.
Summary
What happened
Information disclosure in Apache Tomcat 8.5.7 through 8.5.63 and 9.0.0-M11 through 9.0.43 allows remote attackers to read request data. Http11InputBuffer.fill leaves its ByteBuffer limit and position inconsistent when a socket read fails, so later request parsing can place residual bytes from another request in the default error response. Exploitation requires an incomplete POST to a request-body-reading application and timing with another user's request; the disclosed consequence is cross-user request-body exposure.
The record
- CVE
- CVE-2024-21733
- Published
- Jan 19, 2024
- Updated
- Nov 3, 2025
- Vendor
- The Apache Software Foundation
- Product
- Apache Tomcat
- Classifications
- CWE-209, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 19, 2024CVE 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=8.5.7 <=8.5.63
- Affected versionversion=9.0.0-M11 <=9.0.43
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- CVE-2024-21733 proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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