CVE-2015-5600

Publication date 2 August 2015

Last updated 24 July 2024

Ubuntu priority

Low

Why this priority?

The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.

Read the notes from the security team

Status

Package Ubuntu Release Status
openssh 15.04 vivid
Fixed 1:6.7p1-5ubuntu1.2
14.04 LTS trusty
Fixed 1:6.6p1-2ubuntu2.2
12.04 LTS precise
Fixed 1:5.9p1-5ubuntu1.6

Notes

tyhicks

Only affects systems with KbdInteractiveAuthentication set to 'yes'. By default, that option is set to 'no' in Ubuntu.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
openssh