Hylafax is vulnerable to linking attacks, potentially allowing a local user to overwrite arbitrary files.
|Package||net-misc/hylafax on all architectures|
|Affected versions||< 4.2.2|
|Unaffected versions||revision >= 4.2.0-r3, revision >= 4.2.1-r2, >= 4.2.2|
Hylafax is a client-server fax package for class 1 and 2 fax modems.
Javier Fernandez-Sanguino has discovered that xferfaxstats cron script supplied by Hylafax insecurely creates temporary files with predictable filenames.
A local attacker could create symbolic links in the temporary file directory, pointing to a valid file somewhere on the filesystem. When the xferfaxstats script of Hylafax is executed, this would result in the file being overwritten with the rights of the user running the script, which typically is the root user.
There is no known workaround at this time.
All Hylafax users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose net-misc/hylafax
September 30, 2005
May 22, 2006: 02