SSH Communications Security Information for VU#13877

Weak CRC allows packet injection into SSH sessions encrypted with block ciphers



Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Vendor References



This vulnerability first addressed by incorporating code written by CORE-SDI to detect and block CRC32 attacks. However, an implementation error in this code caused the vulnerability described in VU#945216, which was ultimately addressed in Secure Shell 1.2.32, available at

SSH Communications has released a public statment regarding VU#945216; for more information, please visit

It is important to note that versions 2.x and 3.x of SSH Secure Shell do not serve as replacements for the SSH1 protocol. Rather, they rely upon an existing installation of Secure Shell 1.x to handle SSH1 connections. Thus, installing a version 2.x or 3.x server does not obviate the need to maintain installations of Secure Shell 1.x.

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