CVE-2008-5161
Publication date 19 November 2008
Last updated 24 July 2024
Ubuntu priority
Error handling in the SSH protocol in (1) SSH Tectia Client and Server and Connector 4.0 through 4.4.11, 5.0 through 5.2.4, and 5.3 through 5.3.8; Client and Server and ConnectSecure 6.0 through 6.0.4; Server for Linux on IBM System z 6.0.4; Server for IBM z/OS 5.5.1 and earlier, 6.0.0, and 6.0.1; and Client 4.0-J through 4.3.3-J and 4.0-K through 4.3.10-K; and (2) OpenSSH 4.7p1 and possibly other versions, when using a block cipher algorithm in Cipher Block Chaining (CBC) mode, makes it easier for remote attackers to recover certain plaintext data from an arbitrary block of ciphertext in an SSH session via unknown vectors.
Notes
jdstrand
very difficult to exploit as of 1:5.1p1-5 (Ubuntu 9.04 and later), the packet_disconnect() patch helps mitigate this and should reduce the success probability for the CPNI-957037 Plaintext Recovery Attack to 2^-18. can backport packet_disconnect() patch to 8.10 with next update. Will have to review feasibility of backport to 8.04 and 6.06 at next update. mitigation is to use AES CTR and arcfour ciphers and prefer them using the following line in sshd_config and ssh_config: Ciphers aes128-ctr,aes256-ctr,arcfour256,arcfour,aes128-cbc,aes256-cbc