{"id":"UBUNTU-CVE-2011-1756","details":"modules/xmpp/serv_xmpp.c in Citadel 7.86 and earlier 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a similar issue to CVE-2003-1564.","modified":"2025-07-16T07:30:46.136382Z","published":"2011-06-21T02:52:00Z","withdrawn":"2025-07-18T16:42:42Z","upstream":["CVE-2011-1756"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2011-1756"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2011-1756"}],"affected":[{"package":{"name":"citadel","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/citadel@8.24-1?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.24-1"}]}],"versions":["8.16-1ubuntu1","8.20-1","8.22-1","8.22-2"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"citadel-dbg","binary_version":"8.24-1"},{"binary_name":"citadel-doc","binary_version":"8.24-1"},{"binary_name":"citadel-mta","binary_version":"8.24-1"},{"binary_name":"citadel-server","binary_version":"8.24-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2011/UBUNTU-CVE-2011-1756.json"}}],"schema_version":"1.7.3","severity":[{"type":"Ubuntu","score":"medium"}]}