Apport file permission bypass through emacs byte compilation errors

published 2021-10-01 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26992

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits: 0; none known

Function check_attachment_for_errors() in file data/general-hooks/ubuntu.py could be tricked into exposing private data via a constructed crash file. This issue affects: apport 2.14.1 versions prior to 2.14.1-0ubuntu3.29+esm8; 2.20.1 versions prior to 2.20.1-0ubuntu2.30+esm2; 2.20.9 versions prior to 2.20.9-0ubuntu7.26; 2.20.11 versions prior to 2.20.11-0ubuntu27.20; 2.20.11 versions prior to 2.20.11-0ubuntu65.3;

Patch / fix

fixed in 1 distros 1

Canonical apport 2.14.1-0ubuntu3.29+esm8, 2.20.1-0ubuntu2.30+esm2, 2.20.9-0ubuntu7.26, 2.20.11-0ubuntu27.20, 2.20.11-0ubuntu65.3

apport Ubuntu 18.04 LTS 2.20.9-0ubuntu7.26
apport Ubuntu 20.04 LTS 2.20.11-0ubuntu27.20
apport Ubuntu Pro 14.04 LTS 2.14.1-0ubuntu3.29+esm8
apport Ubuntu Pro 16.04 LTS 2.20.1-0ubuntu2.30+esm2

ubuntu advisories UBUNTU-CVE-2021-3709

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

bugs.launchpad.net https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1934308 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	2.1	AV:L/AC:L/Au:N/C:P/I:N/A:N

Affected products

Canonical apport

Classification

Weakness

CWE-538 Insertion of Sensitive Information into Externally-Accessible File or Directory
CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

bugs.launchpad.net /ubuntu/+source/apport/+bug/1934308
exploit, vendor-advisory
ubuntu.com /security/notices/USN-5077-1
vendor-advisory
ubuntu.com /security/notices/USN-5077-2
vendor-advisory
cve.mitre.org /cgi-bin/cvename.cgi?name=CVE-2021-3709
third-party-advisory

Sources

CVE List CVE-2021-3709
NVD CVE-2021-3709

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary