OpenSSH contains a flaw that may allow a pre-authentication remote denial of service. The issue is triggered when SSH version 1 is used via an SSH packet that contains duplicate blocks, and will result in loss of availability for the service.
Classification
Location:
Remote/Network Access Required
Attack Type:
Cryptographic,
Denial of Service,
Input Manipulation
Impact:
Loss of Availability
Exploit:
Exploit Available
Disclosure:
OSVDB Verified
Technical
This issue can only be exploited when the version 1 SSH protocol is enabled.
Solution
Upgrade to version 4.4 or higher, as it has been reported to fix this vulnerability. It is also possible to correct the flaw by implementing the following workaround(s): disable SSH protocol version 1 in /etc/ssh/sshd_config
google.com - Google Information Security Team