GNU Bash through 4.3 bash43-025 processes trailing strings after certain
malformed function definitions in the values of environment variables,
which allows remote attackers to write to files or possibly have unknown
other impact via a crafted environment, as demonstrated by vectors
involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and
mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified
DHCP clients, and other situations in which setting the environment occurs
across a privilege boundary from Bash execution. NOTE: this vulnerability
exists because of an incomplete fix for CVE-2014-6271.

mdeslaur

mdeslaur

It was discovered that a build issue preventing the fix from being applied properly in the 4.3-7ubuntu1.2 package for Ubuntu 14.04 LTS. A respin was released to 4.3-7ubuntu1.3 to correct the issue, and USN-2363-2 was published.