CVE-2020-8831

Public Exploit
World writable root owned lock file created in user controllable location

Description

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.

Categories

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.10%
Vendor Advisory ubuntu.com
Affected: Canonical Apport
Published at:
Updated at:

References

Link Tags
https://launchpad.net/bugs/1862348 third party advisory exploit
https://usn.ubuntu.com/4315-1/ third party advisory
https://usn.ubuntu.com/4315-2/ third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-8831?
CVE-2020-8831 has been scored as a medium severity vulnerability.
How to fix CVE-2020-8831?
To fix CVE-2020-8831, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-8831 being actively exploited in the wild?
It is possible that CVE-2020-8831 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-8831?
CVE-2020-8831 affects Canonical Apport.
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