Vulnerability Report

CVE-2011-0091

Title: Microsoft Windows Server 2008 Auth Bypass

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2011-0091.

CWE Category CWE-287

Published Date Feb 10, 2011

Modified Date Jun 16, 2026

Exploit Status Not Found

Score 6.4 CVSS v2.0

Exploit Probability (EPSS)

5.49%

Vulnerability Summary

CVE-2011-0091: Kerberos in Microsoft Windows Server 2008 R2 and Windows 7 does not prevent a session from changing from strong encryption to DES encryption, which allows man-in-the-middle attackers to spoof network traffic and obtain sensitive information via a DES downgrade, aka "Kerberos Spoofing Vulnerability."

Impacted Vendors

microsoft 2

Reference Links

http://osvdb.org/70835 http://secunia.com/advisories/43257 http://support.avaya.com/css/P8/documents/100127250 http://www.securityfocus.com/bid/46140 http://www.securitytracker.com/id?1025048 http://www.vupen.com/english/advisories/2011/0326 https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-013 https://exchange.xforce.ibmcloud.com/vulnerabilities/64901 https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12498 http://osvdb.org/70835 http://secunia.com/advisories/43257 http://support.avaya.com/css/P8/documents/100127250 http://www.securityfocus.com/bid/46140 http://www.securitytracker.com/id?1025048 http://www.vupen.com/english/advisories/2011/0326 https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-013 https://exchange.xforce.ibmcloud.com/vulnerabilities/64901 https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12498

CVSS v2.0

Source Entity [email protected]

Severity MEDIUM

6.4

Access Vector

N/A

Authentication

N/A

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

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2011-0091 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.

February 10, 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:P/I:P/A:N

Affected Stack

No specific products linked.