jabberd2 before 2.2.14 does not properly detect recursion during entity expansion, which allows remote attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.

s2s/out.c in jabberd2 2.2.16 and earlier does not verify that a request was made for an XMPP Server Dialback response, which allows remote XMPP servers to spoof domains via a (1) Verify Response or (2) Authorization Response.

c2s/c2s.c in Jabber Open Source Server 2.3.2 and earlier truncates data without ensuring it remains valid UTF-8, which allows remote authenticated users to read system memory or possibly have other unspecified impact via a crafted JID.

JabberD 2.x (aka jabberd2) before 2.6.1 allows anyone to authenticate using SASL ANONYMOUS, even when the sasl.anonymous c2s.xml option is not enabled.

The Gentoo net-im/jabberd2 package through 2.6.1 installs jabberd, jabberd2-c2s, jabberd2-router, jabberd2-s2s, and jabberd2-sm in /usr/bin owned by the jabber account, which might allow local users to gain privileges by leveraging access to this account and then waiting for root to execute one of these programs.

The Gentoo net-im/jabberd2 package through 2.6.1 sets the ownership of /var/run/jabber to the jabber account, which might allow local users to kill arbitrary processes by leveraging access to this account for PID file modification before a root script executes a "kill -TERM `cat /var/run/jabber/filename.pid`" command.