Vulnerabilities > CVE-2011-1075 - Race Condition vulnerability in Freebsd
Attack vector
NETWORK Attack complexity
MEDIUM Privileges required
NONE Confidentiality impact
PARTIAL Integrity impact
NONE Availability impact
NONE Summary
FreeBSD's crontab calculates the MD5 sum of the previous and new cronjob to determine if any changes have been made before copying the new version in. In particular, it uses the MD5File() function, which takes a pathname as an argument, and is called with euid 0. A race condition in this process may lead to an arbitrary MD5 comparison regardless of the read permissions.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| OS | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.