CVE-2009-0129: libcrypt-openssl-dsa-perl does not properly check the return value from the OpenSSL DSA_verify and DSA_do_veri

This month

MEDIUM 5.0WATCHLISTDOWNGRADE

CVE-2009-0129 is a medium-severity flaw (CVSS 5.0) affecting libcrypt-openssl-dsa-perl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

libcrypt-openssl-dsa-perl does not properly check the return value from the OpenSSL DSA_verify and DSA_do_verify functions, which might allow remote attackers to bypass validation of the certificate chain via a malformed SSL/TLS signature, a similar vulnerability to CVE-2008-5077.

Why this priority

Public exploit reference
On your watchlist

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-287
Published	2009-01-15
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: perl-openssl

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

perl-openssl libcrypt-openssl-dsa-perl DOWNGRADE

Affected: _nil_

Fixed in: no fixed release known

Safe to downgrade to: a release before _nil_

1. Check installed version

apt-cache policy libcrypt-openssl-dsa-perl || rpm -q libcrypt-openssl-dsa-perl || libcrypt-openssl-dsa-perl --version

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

apt-cache madison libcrypt-openssl-dsa-perl sudo apt install libcrypt-openssl-dsa-perl=<VERSION_BEFORE__nil_> sudo apt-mark hold libcrypt-openssl-dsa-perl

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

dnf --showduplicates list libcrypt-openssl-dsa-perl sudo dnf downgrade libcrypt-openssl-dsa-perl-<VERSION_BEFORE__nil_> sudo dnf versionlock add libcrypt-openssl-dsa-perl

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-2009-0129?

libcrypt-openssl-dsa-perl: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2009-0129 being exploited?

CVE-2009-0129 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-2009-0129 affect?

CVE-2009-0129 affects libcrypt-openssl-dsa-perl. Severity is medium (CVSS 5.0). libcrypt-openssl-dsa-perl does not properly check the return value from the OpenSSL DSA_verify and DSA_do_verify functions, which might allow remote attackers to bypass validation of the certificate chain via a malformed SSL/TLS signature,

How urgent is CVE-2009-0129?

Priority 44/100. Public exploit reference; On your watchlist

Software pages

OpenSSL vulnerabilities · Perl vulnerabilities

References

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