CVE-2004-0953: Buffer overflow in the C2S module in the open source Jabber 2.x server (Jabberd) allows remote attackers to ca

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HIGH 10.0DOWNGRADE

CVE-2004-0953 is a high-severity flaw (CVSS 10.0) affecting jabber server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the C2S module in the open source Jabber 2.x server (Jabberd) allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a long username.

Why this priority

Critical severity
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	10.0 (High)
EPSS exploit chance	10.7% (top 4%)
CISA exploited list	No
Published	2005-01-10
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: jabber software foundation

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

Am I affected?

Timeline

2005-01-10 05:00 UTCPublished CVE record published
2026-06-16 22:06 UTCUpdated Record last modified

jabber software foundation jabber server DOWNGRADE

Affected: 2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

apt-cache policy jabber-server || rpm -q jabber-server || jabber-server --version

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison jabber-server sudo apt install jabber-server=<VERSION_BEFORE_2.0> sudo apt-mark hold jabber-server

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

dnf --showduplicates list jabber-server sudo dnf downgrade jabber-server-<VERSION_BEFORE_2.0> sudo dnf versionlock add jabber-server

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: Jabber Server 2.0 - Multiple Remote Buffer Overflow Vulnerabilities

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-2004-0953?

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

Is CVE-2004-0953 being exploited?

CVE-2004-0953 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-2004-0953 affect?

CVE-2004-0953 affects jabber server. Severity is high (CVSS 10.0). Buffer overflow in the C2S module in the open source Jabber 2.x server (Jabberd) allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a long username.

How urgent is CVE-2004-0953?

Priority 64/100. Critical severity; EPSS top 4%: very likely to be exploited; Public exploit reference

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References

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