UNIX symbolic link following in libqb - CVE-2019-12779
Published: July 19, 2019
Vulnerability identifier: #VU19263
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2019-12779
CWE-ID: CWE-61
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: ClusterLabs
Affected software:
libqb
libqb
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a symlink following issue because software uses predictable filenames (under /dev/shm and /tmp) without O_EXCL in libqb before 1.0.5. A local user can create a specially crafted symbolic link to a critical file on the system and overwrite it with privileges of the application.
Successful exploitation of this vulnerability may result in privilege escalation.
How to mitigate CVE-2019-12779
Install update from vendor's website.