CVE-2021-32556: It was discovered that the get_modified_conffiles() function in backends/packaging-apt-dpkg.py allowed injecti

Routine

LOW 3.8DOWNGRADE

CVE-2021-32556 is a low-severity flaw (CVSS 3.8) affecting apport. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

It was discovered that the get_modified_conffiles() function in backends/packaging-apt-dpkg.py allowed injecting modified package names in a manner that would confuse the dpkg(1) call.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	3.8 (Low)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-78
Published	2021-06-12
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

2021-06-12 04:15 UTCPublished CVE record published
2026-06-17 03:53 UTCUpdated Record last modified

canonical apport DOWNGRADE

Affected: >= 2.14.1-0ubuntu3 and < 2.14.1-0ubuntu3.29\+esm7 · >= 2.20.1 and < 2.20.1-0ubuntu2.30\+esm1 · >= 2.20.9 and < 2.20.9-0ubuntu7.24 · >= 2.20.11-0ubuntu27 and < 2.20.11-0ubuntu27.18 · >= 2.20.11-0ubuntu50 and < 2.20.11-0ubuntu50.7 · >= 2.20.11-0ubuntu65 and < 2.20.11-0ubuntu65.1

Fixed in: 2.14.1-0ubuntu3.29\+esm7, 2.20.1-0ubuntu2.30\+esm1, 2.20.9-0ubuntu7.24, 2.20.11-0ubuntu27.18, 2.20.11-0ubuntu50.7, 2.20.11-0ubuntu65.1

Safe to downgrade to: a release before 2.14.1-0ubuntu3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.14.1-0ubuntu3 (Debian / Ubuntu)

apt-cache madison apport sudo apt install apport=<VERSION_BEFORE_2.14.1-0ubuntu3> sudo apt-mark hold apport

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

dnf --showduplicates list apport sudo dnf downgrade apport-<VERSION_BEFORE_2.14.1-0ubuntu3> 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-2021-32556?

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

Is CVE-2021-32556 being exploited?

CVE-2021-32556 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-2021-32556 affect?

CVE-2021-32556 affects apport. Severity is low (CVSS 3.8). It was discovered that the get_modified_conffiles() function in backends/packaging-apt-dpkg.py allowed injecting modified package names in a manner that would confuse the dpkg(1) call.

How urgent is CVE-2021-32556?

Priority 20/100. No elevated risk signals yet.

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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