Vulnerability Details : 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.
Vulnerability category: Directory traversalDenial of service
Products affected by CVE-2020-14367
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
- cpe:2.3:a:tuxfamily:chrony:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2020-14367
0.33%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 55 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2020-14367
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
3.6
|
LOW | AV:L/AC:L/Au:N/C:N/I:P/A:P |
3.9
|
4.9
|
NIST | |
|
6.0
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H |
0.8
|
5.2
|
NIST |
CWE ids for CVE-2020-14367
-
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.Assigned by: secalert@redhat.com (Secondary)
-
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.Assigned by:
- nvd@nist.gov (Primary)
- secalert@redhat.com (Secondary)
References for CVE-2020-14367
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6WKABKNLCSC3MACCWU6OM2YGWVWFWFMU/
[SECURITY] Fedora 32 Update: chrony-3.5.1-1.fc32 - package-announce - Fedora Mailing-ListsMailing List;Third Party Advisory
-
https://bugzilla.redhat.com/show_bug.cgi?id=1870298
1870298 – (CVE-2020-14367) CVE-2020-14367 chrony: Insecure writing to PID fileIssue Tracking;Patch;Vendor Advisory
-
https://usn.ubuntu.com/4475-1/
USN-4475-1: Chrony vulnerability | Ubuntu security notices | UbuntuThird Party Advisory
-
https://security.gentoo.org/glsa/202008-23
chrony: Symlink vulnerability (GLSA 202008-23) — Gentoo securityThird Party Advisory
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