CVE-2011-1073

crontab.c in crontab in FreeBSD and Apple Mac OS X allows local users to (1) determine the existence of arbitrary files via a symlink attack on a /tmp/crontab.XXXXXXXXXX temporary file and (2) perform MD5 checksum comparisons on arbitrary pairs of files via two symlink attacks on /tmp/crontab.XXXXXXXXXX temporary files.

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://marc.info/?l=full-disclosure\u0026m=129891323028897\u0026w=2
• http://openwall.com/lists/oss-security/2011/02/28/14
• http://openwall.com/lists/oss-security/2011/02/28/6
• http://securityreason.com/securityalert/8117
• http://www.securityfocus.com/archive/1/516716/100/0/threaded
• http://www.securityfocus.com/bid/46604
• https://exchange.xforce.ibmcloud.com/vulnerabilities/65899