CVE-2021-41497: Null pointer reference in CMS_Conservative_increment_obj in RaRe-Technologies bounter version 1.01 and 1.10, a

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2021-41497 is a high-severity flaw (CVSS 7.5) affecting bounter. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Null pointer reference in CMS_Conservative_increment_obj in RaRe-Technologies bounter version 1.01 and 1.10, allows attackers to conduct Denial of Service attacks by inputting a huge width of hash bucket.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 35%)
CISA exploited list	No
Weakness	CWE-476
Published	2021-12-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: rare-technologies

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

Am I affected?

Timeline

2021-12-17 21:15 UTCPublished CVE record published
2026-06-17 04:08 UTCUpdated Record last modified

rare-technologies bounter DOWNGRADE

Affected: 1.01 · 1.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.01

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.01 (Debian / Ubuntu)

apt-cache madison bounter sudo apt install bounter=<VERSION_BEFORE_1.01> sudo apt-mark hold bounter

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

dnf --showduplicates list bounter sudo dnf downgrade bounter-<VERSION_BEFORE_1.01> sudo dnf versionlock add bounter

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-2021-41497?

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

Is CVE-2021-41497 being exploited?

CVE-2021-41497 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-2021-41497 affect?

CVE-2021-41497 affects bounter. Severity is high (CVSS 7.5). Null pointer reference in CMS_Conservative_increment_obj in RaRe-Technologies bounter version 1.01 and 1.10, allows attackers to conduct Denial of Service attacks by inputting a huge width of hash bucket.

How urgent is CVE-2021-41497?

Priority 52/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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