Vulnerability Details : CVE-2020-8831
Apport creates a world writable lock file with root ownership in the world writable /var/lock/apport directory. If the apport/ directory does not exist (this is not uncommon as /var/lock is a tmpfs), it will create the directory, otherwise it will simply continue execution using the existing directory. This allows for a symlink attack if an attacker were to create a symlink at /var/lock/apport, changing apport's lock file location. This file could then be used to escalate privileges, for example. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.
Products affected by CVE-2020-8831
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
- cpe:2.3:a:apport_project:apport:-:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2020-8831
0.08%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 34 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2020-8831
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
2.1
|
LOW | AV:L/AC:L/Au:N/C:N/I:P/A:N |
3.9
|
2.9
|
NIST | |
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
1.8
|
3.6
|
NIST | |
6.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N |
2.0
|
4.0
|
Canonical Ltd. |
CWE ids for CVE-2020-8831
-
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)
-
The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.Assigned by: security@ubuntu.com (Secondary)
References for CVE-2020-8831
-
https://usn.ubuntu.com/4315-1/
USN-4315-1: Apport vulnerabilities | Ubuntu security noticesThird Party Advisory
-
https://launchpad.net/bugs/1862348
Bug #1862348 “Apport lock file root privilege escalation” : Bugs : apport package : UbuntuExploit;Third Party Advisory
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https://usn.ubuntu.com/4315-2/
USN-4315-2: Apport vulnerabilities | Ubuntu security noticesThird Party Advisory
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