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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2011-4320
• https://support.process-one.net/browse/EJAB-1498
• http://www.openwall.com/lists/oss-security/2011/11/19/1
• http://www.openwall.com/lists/oss-security/2011/11/19/2
• http://www.process-one.net/en/ejabberd/release_notes/release_note_ejabberd_2.1.9
• processone/ejabberd@d3c4eab
• processone/ejabberd@d5b4d67