Joined: 27 Jun 2003
Location: Gothenburg, Sweden
|Posted: Thu Apr 07, 2005 8:06 am Post subject: [ GLSA 200504-06 ] sharutils: Insecure temporary file creati
|Gentoo Linux Security Advisory
Title: sharutils: Insecure temporary file creation (GLSA 200504-06)
Date: April 06, 2005
The unshar utility is vulnerable to symlink attacks, potentially allowing a local user to overwrite arbitrary files.
sharutils is a collection of tools to deal with shar archives.
Vulnerable: < 4.2.1-r11
Unaffected: >= 4.2.1-r11
Architectures: All supported architectures
Joey Hess has discovered that the program unshar, which is a part of sharutils, creates temporary files in a world-writable directory with predictable names.
A local attacker could create symbolic links in the temporary files directory, pointing to a valid file somewhere on the filesystem. When unshar is executed, this would result in the file being overwritten with the rights of the user running the utility, which could be the root user.
There is no known workaround at this time.
All sharutils users should upgrade to the latest version:
|# emerge --sync
# emerge --ask --oneshot --verbose ">=app-arch/sharutils-4.2.1-r11"
Last edited by GLSA on Sat Nov 01, 2008 4:19 am; edited 3 times in total