CVE-2020-8015

A UNIX Symbolic Link (Symlink) Following vulnerability in the packaging of exim in openSUSE Factory allows local attackers to escalate from user mail to root. This issue affects: openSUSE Factory exim versions prior to 4.93.0.4-3.1.

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.opensuse.org/opensuse-security-announce/2020-04/msg00010.html
• https://bugzilla.suse.com/show_bug.cgi?id=1154183