CVE-2021-33294: In elfutils 0.183, an infinite loop was found in the function handle_symtab in readelf.c .Which allows attacke

Routine

MEDIUM 5.5DOWNGRADE

CVE-2021-33294 is a medium-severity flaw (CVSS 5.5) affecting elfutils. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In elfutils 0.183, an infinite loop was found in the function handle_symtab in readelf.c .Which allows attackers to cause a denial of service (infinite loop) via crafted file.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-835
Published	2023-07-18
Last modified	2026-10-14

Publisher (CNA): MITRE · Vendor: elfutils project

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-07-18 14:15 UTCPublished CVE record published
2026-10-14 12:17 UTCUpdated Record last modified

elfutils project elfutils DOWNGRADE

Affected: 0.183

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.183

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.183 (Debian / Ubuntu)

apt-cache madison elfutils sudo apt install elfutils=<VERSION_BEFORE_0.183> sudo apt-mark hold elfutils

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

dnf --showduplicates list elfutils sudo dnf downgrade elfutils-<VERSION_BEFORE_0.183> sudo dnf versionlock add elfutils

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-2021-33294?

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

Is CVE-2021-33294 being exploited?

CVE-2021-33294 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-2021-33294 affect?

CVE-2021-33294 affects elfutils. Severity is medium (CVSS 5.5). In elfutils 0.183, an infinite loop was found in the function handle_symtab in readelf.c .Which allows attackers to cause a denial of service (infinite loop) via crafted file.

How urgent is CVE-2021-33294?

Priority 31/100. Public exploit reference

Related CVEs

CVE-2020-21047 MEDIUM 5.5 DOWNGRADE The libcpu component which is used by libasm of elfutils version 0.177 (git 47780c9e), suffers from denial-of-
CVE-2025-1377 LOW 3.3 DOWNGRADE A vulnerability, which was classified as problematic, has been found in GNU elfutils 0.192
CVE-2025-1376 LOW 2.5 DOWNGRADE A vulnerability classified as problematic was found in GNU elfutils 0.192
CVE-2025-1372 MEDIUM 5.3 DOWNGRADE A vulnerability was found in GNU elfutils 0.192
CVE-2025-1371 LOW 3.3 DOWNGRADE A vulnerability has been found in GNU elfutils 0.192 and classified as problematic

References

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