CVE-2009-2511

Microsoft Windows <7 - Info Disclosure

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2009-2511. PoCs published by Dan Kaminsky.

AI-analyzed exploit summary This exploit demonstrates a vulnerability in Microsoft Internet Explorer where it fails to properly handle encoded values in X.509 certificates, allowing attackers to perform man-in-the-middle attacks or impersonate trusted servers. The provided PKCS#10 certificate requests and private key illustrate the issue with leading zeroes and 64-bit overflow.

Description

Integer overflow in the CryptoAPI component in Microsoft Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7 allows man-in-the-middle attackers to spoof arbitrary SSL servers and other entities via an X.509 certificate that has a malformed ASN.1 Object Identifier (OID) and was issued by a legitimate Certification Authority, aka "Integer Overflow in X.509 Object Identifiers Vulnerability."

Exploits (1)

exploitdb WORKING POC VERIFIED
by Dan Kaminsky · textremotewindows
https://www.exploit-db.com/exploits/33264

This exploit demonstrates a vulnerability in Microsoft Internet Explorer where it fails to properly handle encoded values in X.509 certificates, allowing attackers to perform man-in-the-middle attacks or impersonate trusted servers. The provided PKCS#10 certificate requests and private key illustrate the issue with leading zeroes and 64-bit overflow.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Internet Explorer (versions affected by CVE-2009-2511)
No auth needed
Prerequisites: Ability to generate or intercept X.509 certificates · Target using vulnerable version of Internet Explorer
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (3)

Core 3
Core References
US Government Resource third-party-advisory x_refsource_cert
http://www.us-cert.gov/cas/techalerts/TA09-286A.html
Third Party Advisory, VDB Entry vdb-entry signature x_refsource_oval
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6186

Scores

EPSS 0.1296
EPSS Percentile 95.8%

Details

CWE
CWE-189
Status published
Products (6)
microsoft/windows_2000
microsoft/windows_7
microsoft/windows_server_2003
microsoft/windows_server_2008 (8 CPE variants)
microsoft/windows_vista (3 CPE variants)
microsoft/windows_xp (3 CPE variants)
Published Oct 14, 2009
Tracked Since Feb 18, 2026