CVE-2015-7758

Gummi 0.6.5 allows local users to write to arbitrary files via a symlink attack on a temporary dot file that uses the name of an existing file and a (1) .aux, (2) .log, (3) .out, (4) .pdf, or (5) .toc extension for the file name, as demonstrated by .thesis.tex.aux.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• http://lists.fedoraproject.org/pipermail/package-announce/2016-March/178582.html
• http://lists.fedoraproject.org/pipermail/package-announce/2016-March/178642.html
• http://lists.opensuse.org/opensuse-updates/2015-12/msg00117.html
• http://lists.opensuse.org/opensuse-updates/2016-02/msg00150.html
• http://www.openwall.com/lists/oss-security/2015/10/08/4
• http://www.openwall.com/lists/oss-security/2015/10/08/5
• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=756432