CVE-2021-3709: Function check_attachment_for_errors() in file data/general-hooks/ubuntu.py could be tricked into exposing pri

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MEDIUM 6.5WATCHLISTDOWNGRADE

CVE-2021-3709 is a medium-severity flaw (CVSS 6.5) affecting apport. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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;

Why this priority

Public exploit reference
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-538, CWE-22
Published	2021-10-01
Last modified	2026-06-17

Publisher (CNA): Canonical Ltd. · Vendor: canonical

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-10-01 03:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

canonical apport DOWNGRADE

Affected: 2.14.1-0ubuntu1 · 2.14.1-0ubuntu2 · 2.14.1-0ubuntu3 · 2.14.1-0ubuntu3.1 · 2.14.1-0ubuntu3.2 · 2.14.1-0ubuntu3.3 · 2.14.1-0ubuntu3.4 · 2.14.1-0ubuntu3.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.14.1-0ubuntu1

1. Check installed version

apt-cache policy apport || rpm -q apport || apport --version

2. No fixed release: DOWNGRADE to a release before 2.14.1-0ubuntu1 (Debian / Ubuntu)

apt-cache madison apport sudo apt install apport=<VERSION_BEFORE_2.14.1-0ubuntu1> sudo apt-mark hold apport

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list apport sudo dnf downgrade apport-<VERSION_BEFORE_2.14.1-0ubuntu1> sudo dnf versionlock add apport

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-3709?

apport: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-3709 being exploited?

CVE-2021-3709 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-3709 affect?

CVE-2021-3709 affects apport. Severity is medium (CVSS 6.5). 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 versio

How urgent is CVE-2021-3709?

Priority 43/100. Public exploit reference; On your watchlist

Software pages

Ubuntu vulnerabilities

Related CVEs

CVE-2025-5467 LOW 3.3 UPGRADE It was discovered that process_crash() in data/apport in Canonical's Apport crash reporting tool may create cr
CVE-2025-5054 MEDIUM 4.7 UPGRADE MITIGATE Race condition in Canonical apport up to and including 2.32.0 allows a local attacker to leak sensitive inform
CVE-2023-1326 HIGH 7.7 UPGRADE MITIGATE A privilege escalation attack was found in apport-cli 2.26.0 and earlier which is similar to CVE-2023-26604
CVE-2022-28653 HIGH 7.5 UPGRADE Users can consume unlimited disk space in /var/crash
CVE-2022-1242 HIGH 7.8 UPGRADE MITIGATE Apport can be tricked into connecting to arbitrary sockets as the root user

References

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