OpenSSH < 6.9 Multiple Vulnerabilities
High Nessus Network Monitor Plugin ID 9308
SynopsisThe remote SSH server may be affected by multiple vulnerabilities.
DescriptionVersions of OpenSSH server before 6.9 are affected by the following vulnerabilities :
- A flaw within the 'x11_open_helper()' function in the 'channels.c' file that allows connections to be permitted after 'ForwardX11Timeout' has expired. A remote attacker can exploit this to bypass timeout checks and XSECURITY restrictions. (CVE-2015-5352)
- Various issues were addressed by fixing the weakness in agent locking by increasing the failure delay, storing the salted hash of the password, and using a timing-safe comparison function.
- An out-of-bounds read error exists when handling incorrect pattern lengths. A remote attacker can exploit this to cause a denial of service or disclose sensitive information in the memory.
- An out-of-bounds read error exists when parsing the 'EscapeChar' configuration option.
Note: NNM has solely relied on the banner of the SSH client to perform this check. Any backported patches or workarounds such as recompiling or edited configurations are not observable through the banner.
SolutionUpgrade to OpenSSH version 6.9 or later.