CVE-2004-0270: libclamav in Clam AntiVirus 0.65 allows remote attackers to cause a denial of service (crash) via a uuencoded

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MEDIUM 5.0DOWNGRADE

CVE-2004-0270 is a medium-severity flaw (CVSS 5.0) affecting clamav. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

libclamav in Clam AntiVirus 0.65 allows remote attackers to cause a denial of service (crash) via a uuencoded e-mail message with an invalid line length (e.g., a lowercase character), which causes an assert error in clamd that terminates the calling program.

Why this priority

EPSS top 4%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	10.4% (top 4%)
CISA exploited list	No
Published	2004-11-23
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: clam anti-virus

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

Am I affected?

Timeline

2004-11-23 05:00 UTCPublished CVE record published
2026-06-16 22:05 UTCUpdated Record last modified

clam anti-virus clamav DOWNGRADE

Affected: 0.65

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.65

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.65 (Debian / Ubuntu)

apt-cache madison clamav sudo apt install clamav=<VERSION_BEFORE_0.65> sudo apt-mark hold clamav

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

dnf --showduplicates list clamav sudo dnf downgrade clamav-<VERSION_BEFORE_0.65> sudo dnf versionlock add clamav

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.

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: ClamAV Daemon 0.65 - UUEncoded Message Denial of Service

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-2004-0270?

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

Is CVE-2004-0270 being exploited?

CVE-2004-0270 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-2004-0270 affect?

CVE-2004-0270 affects clamav. Severity is medium (CVSS 5.0). libclamav in Clam AntiVirus 0.65 allows remote attackers to cause a denial of service (crash) via a uuencoded e-mail message with an invalid line length (e.g., a lowercase character), which causes an assert error in clamd that terminates th

How urgent is CVE-2004-0270?

Priority 46/100. EPSS top 4%: very likely to be exploited; Public exploit reference

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References

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