CVE-2019-3696: 
NixOS vulnerability analysis and mitigation

CVE-2019-3696 is a local privilege escalation vulnerability in the Performance Co-Pilot (PCP) software package, specifically in the migrate_tempdirs functionality of the PCP spec file. The vulnerability was discovered in 2019 and affects various versions of Red Hat Enterprise Linux 7 and SUSE Linux Enterprise systems (Red Hat Advisory, SUSE Bug).

The vulnerability exists in the migrate_tempdirs function where a malicious local user could exploit the mv command to perform privilege escalation. The issue is classified as CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) (NVD CWE). The vulnerability can be exploited by creating specific directory structures and symbolic links in /var/tmp/pmlogger and /var/lib/pcp/tmp/pmlogger directories (SUSE Bug).

If successfully exploited, this vulnerability allows a local attacker to escalate privileges on the affected system. The attacker could potentially modify critical system files, such as /etc/passwd, leading to complete system compromise (SUSE Bug).

Updates have been released to address this vulnerability. SUSE has released security updates SUSE-SU-2020:0355-1, SUSE-SU-2020:0356-1, and SUSE-SU-2020:0357-1 for various affected products. Red Hat has addressed this issue in RHSA-2020:3869 for Red Hat Enterprise Linux 7 (Red Hat Advisory, SUSE Bug).