The RPM Package Manager (RPM) is a powerful command line driven package management system capable of installing, uninstalling, verifying, querying, and updating software packages. Each software package consists of an archive of files along with information about the package such as its version, description, and other information.
It was found that RPM wrote file contents to the target installation directory under a temporary name, and verified its cryptographic signature only after the temporary file has been written completely. Under certain conditions, the system interprets the unverified temporary file contents and extracts commands from it. This could allow an attacker to modify signed RPM files in such a way that they would execute code chosen by the attacker during package installation. (CVE-2013-6435)
This issue was discovered by Florian Weimer of Red Hat Product Security.
All rpm users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. All running applications linked against the RPM library must be restarted for this update to take effect.