Session integrity bypass via SSH prefix truncation
Published Aug 12, 2024 · Updated Mar 27, 2025
Improper SSH packet integrity validation in Apache MINA SSHD 2.11.0 and earlier allows man-in-the-middle attackers to alter sessions. During initial key exchange, the transport permits non-KEX packets and retains sequence numbers across NEW_KEYS, enabling an interceptor to inject packets and delete an equal-length encrypted prefix without detection. Exploitation requires traffic interception and a susceptible client-server algorithm combination; successful truncation can disable negotiated security features without terminating the session.
Summary
What happened
Improper SSH packet integrity validation in Apache MINA SSHD 2.11.0 and earlier allows man-in-the-middle attackers to alter sessions. During initial key exchange, the transport permits non-KEX packets and retains sequence numbers across NEW_KEYS, enabling an interceptor to inject packets and delete an equal-length encrypted prefix without detection. Exploitation requires traffic interception and a susceptible client-server algorithm combination; successful truncation can disable negotiated security features without terminating the session.
The record
- CVE
- CVE-2024-41909
- Published
- Aug 12, 2024
- Updated
- Mar 27, 2025
- Vendor
- The Apache Software Foundation
- Product
- Apache MINA SSHD
- Classifications
- CWE-354, T1565.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 12, 2024CVE publishedPublication date reported by the CVE source.
- Mar 27, 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=0 <=2.11.0
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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