Shorewall : Insecure temp file handling — GLSA 200407-07

Shorewall contains a bug in the code handling the creation of temporary files and directories. This can allow a non-root user to overwrite arbitrary system files.

Affected packages

Package 	net-firewall/shorewall on all architectures
Affected versions 	<= 1.4.10c
Unaffected versions 	>= 1.4.10f

Background

Shorewall is a high level tool for configuring Netfilter, the firewall facility included in the Linux Kernel.

Description

Shorewall uses temporary files and directories in an insecure manner. A local user could create symbolic links at specific locations, eventually overwriting other files on the filesystem with the rights of the shorewall process.

Impact

An attacker could exploit this vulnerability to overwrite arbitrary system files with root privileges, resulting in Denial of Service or further exploitation.

Workaround

There is no known workaround at this time. All users should upgrade to the latest available version of Shorewall.

Resolution

All users should upgrade to the latest available version of Shorewall, as follows:

 # emerge sync
 
 # emerge -pv ">=net-firewall/shorewall-1.4.10f"
 # emerge ">=net-firewall/shorewall-1.4.10f"

References

    Shorewall Announcement
    CVE-2004-0647