CVE-2009-0125: NOTE: this issue has been disputed by the upstream vendor

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MEDIUM 5.0DOWNGRADE

CVE-2009-0125 is a medium-severity flaw (CVSS 5.0) affecting libnasl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

NOTE: this issue has been disputed by the upstream vendor. nasl/nasl_crypto2.c in the Nessus Attack Scripting Language library (aka libnasl) 2.2.11 does not properly check the return value from the OpenSSL DSA_do_verify function, which allows remote attackers to bypass validation of the certificate chain via a malformed SSL/TLS signature, a similar vulnerability to CVE-2008-5077. NOTE: the upstream vendor has disputed this issue, stating "while

Why this priority

Public exploit reference

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	1.5% (top 26%)
CISA exploited list	No
Weakness	CWE-287
Published	2009-01-15
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: finkproject

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2009-01-15 17:30 UTCPublished CVE record published
2026-06-16 23:04 UTCUpdated Record last modified

finkproject libnasl DOWNGRADE

Affected: 2.2.11

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.2.11

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.2.11 (Debian / Ubuntu)

apt-cache madison libnasl sudo apt install libnasl=<VERSION_BEFORE_2.2.11> sudo apt-mark hold libnasl

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

dnf --showduplicates list libnasl sudo dnf downgrade libnasl-<VERSION_BEFORE_2.2.11> sudo dnf versionlock add libnasl

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-2009-0125?

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

Is CVE-2009-0125 being exploited?

CVE-2009-0125 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-2009-0125 affect?

CVE-2009-0125 affects libnasl. Severity is medium (CVSS 5.0). NOTE: this issue has been disputed by the upstream vendor. nasl/nasl_crypto2.c in the Nessus Attack Scripting Language library (aka libnasl) 2.2.11 does not properly check the return value from the OpenSSL DSA_do_verify function, which allo

How urgent is CVE-2009-0125?

Priority 41/100. Public exploit reference

Software pages

OpenSSL vulnerabilities

References

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