Russh has an OOM Denial of Service due to allocation of untrusted amount
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.9%
exploitation probability
0.9%top 43% of all CVEs
observed exploitation
nono source reports it
Russh is a Rust SSH client & server library. Allocating an untrusted amount of memory allows any unauthenticated user to OOM a russh server. An SSH packet consists of a 4-byte big-endian length, followed by a byte stream of this length.
After parsing and potentially decrypting the 4-byte length, russh allocates enough memory for this bytestream, as a performance optimization to avoid reallocations later. But this length is entirely untrusted and can be set to any value by the client, causing this much memory to be allocated, which will cause the process to OOM within a few such requests. This vulnerability is fixed in 0.44.1.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Eugeny · russh