Vulnerability in Tuxfamily Chrony
CVE-2020-14367
A flaw was found in chrony versions before 3.5.1 when creating the PID file under the /var/run/chrony folder. The file is created during chronyd startup while still running as the root user, and when it's opened for writing, chronyd does not check for an existing symbolic link with the same file name. This flaw allows an attacker with privileged access to create a symlink with the default PID file name pointing to any destination file in the system, resulting in data loss and a denial of service due to the path traversal.
EPSS: 0.005 (39.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H.
Affected products
- Tuxfamily Chrony
- Canonical Ubuntu_linux — versions 18.04, 20.04
- Fedoraproject Fedora — versions 32
- N/a Chrony — versions All chrony versions before 3.5.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- secalert@redhat.com (x_refsource_FEDORA, vendor-advisory)
- secalert@redhat.com (Patch, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- secalert@redhat.com (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- secalert@redhat.com (x_refsource_UBUNTU, vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-14367?
- CVE-2020-14367 is a medium-severity vulnerability in Tuxfamily Chrony, classified under Improper Link Resolution Before File Access. CVSS score: 6.0/10. Published 2020-08-24.
- How severe is CVE-2020-14367?
- Medium severity. CVSS v3 base score is 6.0 out of 10.
- Is CVE-2020-14367 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.