PT-2020-20314 · Canonical · Apport+1

Maximilien Bourgeteau · Published 2020-04-02 · Updated 2022-10-07 · CVE-2020-8833

Positive Technologies (AI Summary)

CVSS v3.1

5.6

Medium

Base vector

AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions Apport versions prior to 2.20.1-0ubuntu2.23 Apport versions prior to 2.20.9-0ubuntu7.14 Apport versions prior to 2.20.11-0ubuntu8.8 Apport versions prior to 2.20.11-0ubuntu22

Description A Time-of-check Time-of-use Race Condition issue exists in Apport related to crash report ownership change. This can potentially allow for privilege escalation if the fs.protected symlinks setting is disabled. The vulnerability can be exploited between the os.open and os.chown calls when the Apport cron script removes crash files of size 0. An attacker can create a symlink with the same name as the deleted file, and then the chown call will change the file owner to root.

Recommendations For Apport version prior to 2.20.1-0ubuntu2.23, update to version 2.20.1-0ubuntu2.23 or later. For Apport version prior to 2.20.9-0ubuntu7.14, update to version 2.20.9-0ubuntu7.14 or later. For Apport version prior to 2.20.11-0ubuntu8.8, update to version 2.20.11-0ubuntu8.8 or later. For Apport version prior to 2.20.11-0ubuntu22, update to version 2.20.11-0ubuntu22 or later.

Exploit

Fix

Time Of Check To Time Of Use

Weakness Enumeration

CWE-367

Related Identifiers

CVE-2020-8833

USN-4315-1

USN-4315-2

Affected Products

Apport

Ubuntu

References · 13

• 🔥 https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933 · Exploit
• https://usn.ubuntu.com/4315-2 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-8831 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-4315-2 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-8833 · Security Note
• https://osv.dev/vulnerability/USN-4315-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-8833 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2020-8833 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2020-8833 · Security Note
• https://ubuntu.com/security/notices/USN-4315-1 · Vendor Advisory
• https://osv.dev/vulnerability/USN-4315-2 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2020-8833 · Vendor Advisory
• https://usn.ubuntu.com/4315-1 · Note