pageant: unbounded frame buffering on peer-controlled 4-byte length prefix (memory-exhaustion DoS)
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 0.2.5
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The pageant Rust crate, which provides the PageantStream type for communicating with a running Pageant SSH agent, is affected. A malicious SSH server could send a crafted length prefix that makes applications bridging the forwarded-agent channel allocate excessive memory, potentially exhausting the client's memory.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
pageant provides a PageantStream type that implements AsyncRead and AsyncWrite traits and can be used to communicate with a running Pageant instance. From 0.2.0 until 0.2.5, PageantStream::new in pageant/src/wmmessage.rs trusts a peer-controlled four-byte length prefix and buffers until len + 4 bytes are available without checking the fixed _AGENT_MAX_MSGLEN transport capacity. An application that bridges an SSH forwarded-agent channel to the raw stream can allow a malicious server to force large allocations or retain a partially filled frame, causing client memory exhaustion. This issue is fixed in version 0.2.5.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- Eugeny russh
From 0.2.0 · fixed in 0.2.5