A buffer overflow has been discovered in the PCRE, a widely used library that provides Perl compatible regular expressions. Specially crafted regular expressions triggered a buffer overflow. On systems that accept arbitrary regular expressions from untrusted users, this could be exploited to execute arbitrary code with the privileges of the application using the library.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/39564/USN-173-1.txt
Source: https://packetstormsecurity.com/files/39564/Ubuntu-Security-Notice-173-1.html