CVE-2021-34122: The function bitstr_tell at bitstr.c in ffjpeg commit 4ab404e has a NULL pointer dereference.

Q: How do I fix CVE-2021-34122?

ffjpeg: upgrade to 2021-03-16. Exact commands for each OS are on this page.

Q: Is CVE-2021-34122 being exploited?

CVE-2021-34122 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-34122 affect?

CVE-2021-34122 affects ffjpeg. Severity is medium (CVSS 5.5). The function bitstr_tell at bitstr.c in ffjpeg commit 4ab404e has a NULL pointer dereference.

Q: How urgent is CVE-2021-34122?

Priority 39/100. Public exploit reference

Routine

MEDIUM 5.5UPGRADE

CVE-2021-34122 is a medium-severity flaw (CVSS 5.5) affecting ffjpeg. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The function bitstr_tell at bitstr.c in ffjpeg commit 4ab404e has a NULL pointer dereference.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-476
Published	2022-03-10
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: rockcarry

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

Am I affected?

Timeline

2022-03-10 17:42 UTCPublished CVE record published
2026-06-17 03:55 UTCUpdated Record last modified

rockcarry ffjpeg UPGRADE

Affected: < 2021-03-16

Fixed in: 2021-03-16

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2021-03-16 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ffjpeg

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ffjpeg

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2021-34122?

ffjpeg: upgrade to 2021-03-16. Exact commands for each OS are on this page.

Is CVE-2021-34122 being exploited?

CVE-2021-34122 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-2021-34122 affect?

CVE-2021-34122 affects ffjpeg. Severity is medium (CVSS 5.5). The function bitstr_tell at bitstr.c in ffjpeg commit 4ab404e has a NULL pointer dereference.

How urgent is CVE-2021-34122?

Priority 39/100. Public exploit reference

Related CVEs

CVE-2022-35433 MEDIUM 6.5 UPGRADE ffjpeg commit caade60a69633d74100bd3c2528bddee0b6a1291 was discovered to contain a memory leak via /src/jfif.c
CVE-2022-28471 MEDIUM 6.5 DOWNGRADE In ffjpeg (commit hash: caade60), the function bmp_load() in bmp.c contains an integer overflow vulnerability,
CVE-2021-45385 MEDIUM 6.5 DOWNGRADE A Null Pointer Dereference vulnerability exits in ffjpeg d5cfd49 (2021-12-06) in bmp_load()
CVE-2021-44957 MEDIUM 6.5 UPGRADE Global buffer overflow vulnerability exist in ffjpeg through 01.01.2021
CVE-2021-44956 MEDIUM 6.5 UPGRADE Two Heap based buffer overflow vulnerabilities exist in ffjpeg through 01.01.2021

References

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