CVE-2019-11481

Kevin Backhouse discovered that apport would read a user-supplied configuration file with elevated privileges. By replacing the file with a symbolic link, a user could get apport to read any file on the system as root, with unknown consequences.

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://packetstormsecurity.com/files/172858/Ubuntu-Apport-Whoopsie-DoS-Integer-Overflow.html
• https://usn.ubuntu.com/usn/usn-4171-1
• https://usn.ubuntu.com/usn/usn-4171-2