RedHat Glint /tmp Symbolic Link Vulnerability

Glint is an rpm installation tool shipped with RedHat Linux. Glint is vulnerable to an attack related to its use of temporary files in the world writeable /tmp directory. The files are reportedly created by Glint with predictable filenames and Glint follows symlinks if the files already exist when they are written to. As a result, it is possible for an attacker to create symbolic links in /tmp with filenames that will be the ones Glint will use before Glint is run, that point to crticial system files. When Glint is run by root, presumably to install an rpm (which is a pretty typical administration task), the files pointed to by the symbolic links with correctly anticipated filenames will be overwritten. This can lead to a denial of service on the system (if, say, /etc/passwd was overwritten).

Though glint is not setuid root, it is meant to be run by root (it is used to install software in directories only root can write to) so an attacker could create the symbolic links and then wait for root to run it. This bug only affects older RedHat systems, and rpm 3.0 obsoleted Glint, so systems with this version can remove Glint if it is present.


 

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