CVE-2011-4320: The mod_pubsub module (mod_pubsub.erl) in ejabberd 2.1.8 and 3.0.0-alpha-3 allows remote authenticated users t

Routine

MEDIUM 4.0DOWNGRADE

CVE-2011-4320 is a medium-severity flaw (CVSS 4.0) affecting ejabberd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The mod_pubsub module (mod_pubsub.erl) in ejabberd 2.1.8 and 3.0.0-alpha-3 allows remote authenticated users to cause a denial of service (infinite loop) via a stanza with a publish tag that lacks a node attribute.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	4.0 (Medium)
EPSS exploit chance	2.0% (top 19%)
CISA exploited list	No
Weakness	CWE-399
Published	2012-02-18
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: process-one

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

Am I affected?

Timeline

2012-02-18 00:55 UTCPublished CVE record published
2026-06-16 23:34 UTCUpdated Record last modified

process-one ejabberd DOWNGRADE

Affected: 2.1.8 · 3.0.0 alpha3

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.1.8

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.1.8 (Debian / Ubuntu)

apt-cache madison ejabberd sudo apt install ejabberd=<VERSION_BEFORE_2.1.8> sudo apt-mark hold ejabberd

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

dnf --showduplicates list ejabberd sudo dnf downgrade ejabberd-<VERSION_BEFORE_2.1.8> sudo dnf versionlock add ejabberd

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-2011-4320?

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

Is CVE-2011-4320 being exploited?

CVE-2011-4320 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-2011-4320 affect?

CVE-2011-4320 affects ejabberd. Severity is medium (CVSS 4.0). The mod_pubsub module (mod_pubsub.erl) in ejabberd 2.1.8 and 3.0.0-alpha-3 allows remote authenticated users to cause a denial of service (infinite loop) via a stanza with a publish tag that lacks a node attribute.

How urgent is CVE-2011-4320?

Priority 34/100. No elevated risk signals yet.

Related CVEs

CVE-2014-8760 MEDIUM 5.0 UPGRADE ejabberd before 2.1.13 does not enforce the starttls_required setting when compression is used, which causes c
CVE-2013-6169 MEDIUM 4.3 UPGRADE The TLS driver in ejabberd before 2.1.12 supports (1) SSLv2 and (2) weak SSL ciphers, which makes it easier fo

References

← Back to latest CVEs