Russh: Post-decompression SSH packet size was not bounded, allowing remote oversized compressed packets
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.3%
exploitation probability
0.3%top 81% of all CVEs
observed exploitation
nono source reports it
Russh is a Rust SSH client & server library. From version 0.34.0 to before version 0.61.1, when SSH compression is enabled, russh accepted compressed packets whose on-wire size passed the normal transport packet-length checks but whose decompressed size was much larger. This allowed a remote peer to send oversized post-decompression packets that should have been rejected. In current releases, this is a remote denial-of-service / resource-exhaustion issue in the post-decompression receive path. In older releases before 0.58.0, the same remote decompression path used CryptoVec, which appears to make the historical impact worse. This issue has been patched in version 0.61.1.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Eugeny · russh