CVE-2009-1391: Off-by-one error in the inflate function in Zlib.xs in Compress::Raw::Zlib Perl module before 2.017, as used i

Q: How do I fix CVE-2009-1391?

compress-raw-zlib perl module: upgrade to newer than 2.015. Exact commands for each OS are on this page.

Q: Is CVE-2009-1391 being exploited?

CVE-2009-1391 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-2009-1391 affect?

CVE-2009-1391 affects compress-raw-zlib perl module. Severity is medium (CVSS 6.8). Off-by-one error in the inflate function in Zlib.xs in Compress::Raw::Zlib Perl module before 2.017, as used in AMaViS, SpamAssassin, and possibly other products, allows context-dependent attackers to cause a denial of service (hang or cras

Q: How urgent is CVE-2009-1391?

Priority 52/100. EPSS top 6%: very likely to be exploited; Public exploit reference

This month

MEDIUM 6.8UPGRADE

CVE-2009-1391 is a medium-severity flaw (CVSS 6.8) affecting compress-raw-zlib perl module. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Off-by-one error in the inflate function in Zlib.xs in Compress::Raw::Zlib Perl module before 2.017, as used in AMaViS, SpamAssassin, and possibly other products, allows context-dependent attackers to cause a denial of service (hang or crash) via a crafted zlib compressed stream that triggers a heap-based buffer overflow, as exploited in the wild by Trojan.Downloader-71014 in June 2009.

Why this priority

EPSS top 6%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	7.4% (top 6%)
CISA exploited list	No
Weakness	CWE-189
Published	2009-06-16
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: paul marquess

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

Am I affected?

Timeline

2009-06-16 23:30 UTCPublished CVE record published
2026-06-16 23:07 UTCUpdated Record last modified

paul marquess compress-raw-zlib perl module UPGRADE

Affected: <= 2.015 · 2.001 · 2.002 · 2.003 · 2.004 · 2.005 · 2.006 · 2.008

Fixed in: newer than 2.015

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy compress-raw-zlib-perl-module || rpm -q compress-raw-zlib-perl-module || compress-raw-zlib-perl-module --version

2. UPGRADE to newer than 2.015 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade compress-raw-zlib-perl-module

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade compress-raw-zlib-perl-module

Note

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

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Compress::Raw::Zlib Perl Module - Remote Code Execution

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-2009-1391?

compress-raw-zlib perl module: upgrade to newer than 2.015. Exact commands for each OS are on this page.

Is CVE-2009-1391 being exploited?

CVE-2009-1391 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-2009-1391 affect?

CVE-2009-1391 affects compress-raw-zlib perl module. Severity is medium (CVSS 6.8). Off-by-one error in the inflate function in Zlib.xs in Compress::Raw::Zlib Perl module before 2.017, as used in AMaViS, SpamAssassin, and possibly other products, allows context-dependent attackers to cause a denial of service (hang or cras

How urgent is CVE-2009-1391?

Priority 52/100. EPSS top 6%: very likely to be exploited; Public exploit reference

Software pages

Perl vulnerabilities · zlib vulnerabilities

References

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