Description (CNA)
libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| libssh2 / libssh2 | affected 0 through 1.11.1; unaffected 17626857d20b3c9a1addfa45979dadcee1cd84a4 |
CWE
CWE-835
References
- https://github.com/libssh2/libssh2/pull/1864
- https://github.com/libssh2/libssh2/commit/17626857d20b3c9a1addfa45979dadcee1cd84a4
- https://www.vulncheck.com/advisories/libssh2-pre-authentication-dos-via-ssh-msg-ext-info-handler
ADP enrichment
No English description supplied.
No references supplied.