MEDIUM
CVE-2011-1756
CWE-399Published: June 21, 2011· Updated: Jun 16, 2026
5.0
CVSS v3.1
Official Description
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.
Technical Analysis
CVE-2011-1756 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.
User Interaction
Scope
Impact
ConfidentialityNone
IntegrityNone
AvailabilityP
AV:N/AC:L/Au:N/C:N/I:N/A:P
Affected Vendors & Products
citadel1 product(s)
citadel
Source: NVD CPE · 8 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
PATCHhttp://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=27c991cc2059f5530d3d4e9689dc976b745f5b0c
PATCHhttp://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=95040add546a705cc2d1d8f16293141f9f9845a6
PATCHhttp://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=27c991cc2059f5530d3d4e9689dc976b745f5b0c
All References (16)
→
→
→
http://secunia.com/advisories/44788Vendor Advisory
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http://secunia.com/advisories/44788Vendor Advisory
Quick Facts
CVE IDCVE-2011-1756
CVSS Score5.0 / 10
SeverityMEDIUM
WeaknessCWE-399
CISA KEVNo
Affected1 vendor(s)
PublishedJun 21, 2011
Related CVEs (CWE-399)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2011-1756 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.