Race condition in Snapd - CVE-2019-11503
Published: April 30, 2019 / Updated: January 29, 2020
Vulnerability identifier: #VU18375
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-11503
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition when processing symlinks using the chdir() function to restore a working directory. A local user can run snap-confine on a specially crafted symlink and restore files without necessary permissions.
Affected software
Snapd
Fedora
snapd-glib
Fedora
snapd-glib
How to mitigate CVE-2019-11503
Install update from vendor's website.
Snapd - update to 2.39
snapd-glib - addressed in versions 1.48-1.el7, 1.48-1.fc29, 1.48-1.fc30
snapd-glib - addressed in versions 1.48-1.el7, 1.48-1.fc29, 1.48-1.fc30