Vulnerability Report

CVE-2011-1756

Title: Citadel Denial of Service (DoS)

DoS

Proof Of Concept

No public PoC currently indexed for CVE-2011-1756.

CWE Category CWE-399

Published Date Jun 21, 2011

Modified Date Jun 16, 2026

Exploit Status Not Found

Score 5.0 CVSS v2.0

Exploit Probability (EPSS)

2.66%

Vulnerability Summary

CVE-2011-1756: 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.

Impacted Vendors

citadel 1

Reference Links

http://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=27c991cc2059f5530d3d4e9689dc976b745f5b0c http://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=95040add546a705cc2d1d8f16293141f9f9845a6 http://packages.debian.org/changelogs/pool/main/c/citadel/citadel_7.37-8+lenny1/changelog http://packages.debian.org/changelogs/pool/main/c/citadel/citadel_7.83-2squeeze2/changelog http://secunia.com/advisories/44788 http://security.debian.org/debian-security/pool/updates/main/c/citadel/citadel_7.83-2squeeze2.diff.gz http://www.debian.org/security/2011/dsa-2250 http://www.securityfocus.com/bid/48071 http://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=27c991cc2059f5530d3d4e9689dc976b745f5b0c http://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=95040add546a705cc2d1d8f16293141f9f9845a6 http://packages.debian.org/changelogs/pool/main/c/citadel/citadel_7.37-8+lenny1/changelog http://packages.debian.org/changelogs/pool/main/c/citadel/citadel_7.83-2squeeze2/changelog http://secunia.com/advisories/44788 http://security.debian.org/debian-security/pool/updates/main/c/citadel/citadel_7.83-2squeeze2.diff.gz http://www.debian.org/security/2011/dsa-2250 http://www.securityfocus.com/bid/48071

CVSS v2.0

Source Entity [email protected]

Severity MEDIUM

5.0

Access Vector

N/A

Authentication

N/A

RAW VECTOR AV:N/AC:L/Au:N/C:N/I:N/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2011-1756 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

June 16, 2026 MODIFIED

Vulnerability data updated via NVD.

April 29, 2026 MODIFIED

Vulnerability data updated via NVD.

April 11, 2025 MODIFIED

Vulnerability data or affected products updated.

June 21, 2011 PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector N/A

Complexity N/A

Privileges N/A

Interaction NONE

CVSS Vector String


                                    AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected Stack

No specific products linked.