Today, a working exploit has appeared on the network for all versions of Linux from 2.6.37 to 3.8.10 , which allows a local user to get root. The problem is complicated by the fact that in the case of RHEL / CentOS 6, the vulnerability was backported to the 2.6.32 kernel, so that the owners of servers with these systems should also hope for an early release of the kernel and the correction of the error. Thus, all major releases of the most popular server distributions turned out to be vulnerable: Debian 7.0, RHEL / CentOS 6, Ubuntu 12.04.
UPD: exploit for x86_64 / amd64, it is necessary to compile with -O2 what is said in the source code.