CVE-2018-1121

procps-ng, procps is vulnerable to a process hiding through race condition. Since the kernels proc_pid_readdir() returns PID entries in ascending numeric order, a process occupying a high PID can use inotify events to determine when the process list is being scanned, and fork/exec to obtain a lower PID, thus avoiding enumeration. An unprivileged attacker can hide a process from procps-ngs utilities by exploiting a race condition in reading /proc/PID entries. This vulnerability affects procps and procps-ng up to version 3.3.15, newer versions might be affected also.

Weakness

The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.

Affected Software

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/27.html
• https://cwe.mitre.org/data/definitions/29.html

References

• http://seclists.org/oss-sec/2018/q2/122
• http://www.securityfocus.com/bid/104214
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1121
• https://www.exploit-db.com/exploits/44806/
• https://www.qualys.com/2018/05/17/procps-ng-audit-report-advisory.txt
• http://seclists.org/oss-sec/2018/q2/122
• http://www.securityfocus.com/bid/104214
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1121
• https://www.exploit-db.com/exploits/44806/
• https://www.qualys.com/2018/05/17/procps-ng-audit-report-advisory.txt