CVE-2004-0891: Buffer overflow in the MSN protocol handler for gaim 0.79 to 1.0.1 allows remote attackers to cause a denial o

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HIGH 10.0WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2004-0891 is a high-severity flaw (CVSS 10.0) affecting gaim, linux, slackware linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the MSN protocol handler for gaim 0.79 to 1.0.1 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via an "unexpected sequence of MSNSLP messages" that results in an unbounded copy operation that writes to the wrong buffer.

Why this priority

Critical severity
EPSS top 6%: very likely to be exploited
On your watchlist

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

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	6.9% (top 6%)
CISA exploited list	No
Published	2005-01-27
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: gentoo · rob flynn · slackware · ubuntu

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

Am I affected?

Timeline

2005-01-27 05:00 UTCPublished CVE record published
2026-06-16 22:06 UTCUpdated Record last modified

rob flynn gaim DOWNGRADE

Affected: 0.10 · 0.10.3 · 0.50 · 0.51 · 0.52 · 0.53 · 0.54 · 0.55

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.10

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.10 (Debian / Ubuntu)

apt-cache madison gaim sudo apt install gaim=<VERSION_BEFORE_0.10> sudo apt-mark hold gaim

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

dnf --showduplicates list gaim sudo dnf downgrade gaim-<VERSION_BEFORE_0.10> sudo dnf versionlock add gaim

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.

gentoo linux MITIGATE

Affected: all versions · 1.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

slackware slackware linux MITIGATE

Affected: 9.0 · 9.1 · 10.0 · current

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

ubuntu ubuntu linux MITIGATE

Affected: 4.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2004-0891?

gaim: downgrade or apply the listed mitigation; linux: mitigate or apply the listed mitigation; slackware linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2004-0891 being exploited?

CVE-2004-0891 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-2004-0891 affect?

CVE-2004-0891 affects gaim, linux, slackware linux. Severity is high (CVSS 10.0). Buffer overflow in the MSN protocol handler for gaim 0.79 to 1.0.1 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via an "unexpected sequence of MSNSLP messages" that results in

How urgent is CVE-2004-0891?

Priority 64/100. Critical severity; EPSS top 6%: very likely to be exploited; On your watchlist

Software pages

Ubuntu vulnerabilities

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References

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