CVE-2011-0541

fuse 2.8.5 and earlier does not properly handle when /etc/mtab cannot be updated, which allows local users to unmount arbitrary directories via a symlink attack.

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://fuse.git.sourceforge.net/git/gitweb.cgi?p=fuse/fuse%3Ba=commit%3Bh=bf5ffb5fd8558bd799791834def431c0cee5a11f
• http://lists.opensuse.org/opensuse-security-announce/2011-04/msg00000.html
• http://www.openwall.com/lists/oss-security/2011/02/02/2
• http://www.openwall.com/lists/oss-security/2011/02/03/5
• http://www.openwall.com/lists/oss-security/2011/02/08/4