CVE-2015-1338

kernel_crashdump in Apport before 2.19 allows local users to cause a denial of service (disk consumption) or possibly gain privileges via a (1) symlink or (2) hard link attack on /var/crash/vmcore.log.

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/133723/Ubuntu-Apport-kernel_crashdump-Symlink.html
• http://seclists.org/fulldisclosure/2015/Sep/101
• http://www.halfdog.net/Security/2015/ApportKernelCrashdumpFileAccessVulnerabilities/
• http://www.ubuntu.com/usn/USN-2744-1
• https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1492570
• https://launchpad.net/apport/trunk/2.19
• https://www.exploit-db.com/exploits/38353/