Ubuntu Security Notice USN-3061-1
15th August, 2016
openssh vulnerabilities
A security issue affects these releases of Ubuntu and its
derivatives:
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS
Summary
Several security issues were fixed in OpenSSH.
Software description
- openssh
– secure shell (SSH) for secure access to remote machines
Details
Eddie Harari discovered that OpenSSH incorrectly handled password hashing
when authenticating non-existing users. A remote attacker could perform a
timing attack and enumerate valid users. (CVE-2016-6210)
Tomas Kuthan, Andres Rojas, and Javier Nieto discovered that OpenSSH did
not limit password lengths. A remote attacker could use this issue to cause
OpenSSH to consume resources, leading to a denial of service.
(CVE-2016-6515)
Update instructions
The problem can be corrected by updating your system to the following
package version:
- Ubuntu 16.04 LTS:
-
openssh-server
1:7.2p2-4ubuntu2.1
- Ubuntu 14.04 LTS:
-
openssh-server
1:6.6p1-2ubuntu2.8
- Ubuntu 12.04 LTS:
-
openssh-server
1:5.9p1-5ubuntu1.10
To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.