How severe is CVE-2011-1889?

CVE-2011-1889 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2011-1889?

Affected package information for CVE-2011-1889 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2011-1889?

No fixed version has been published for CVE-2011-1889 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2011-1889 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2011-1889, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2011-1889?

CVE-2011-1889 has an EPSS (Exploit Prediction Scoring System) score of 88.1%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2011-1889 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2011-1889 (Microsoft Forefront TMG Remote Code Execution Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-03-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-03-24. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2011-1889?

CVE-2011-1889 is classified as Buffer Overflow (CWE-119). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2011-1889?

CVE-2011-1889 affects microsoft forefront threat management gateway (1 version, e.g. 2010). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2011-1889 published, and has it been updated?

CVE-2011-1889 was published on June 16, 2011 and was last updated on April 22, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-03-03 — agencies required to remediate by 2022-03-24

CVE-2011-1889

CRITICAL

The NSPLookupServiceNext function in the client in Microsoft Forefront Threat Management Gateway (TMG) 2010 allows remote attackers to execute arbitrary code via vectors involving unspecified…

Published

Jun 16, 2011

Updated

Apr 22, 2026

Affected

0 pkgs

Patched

None yet

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

88.1%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

The NSPLookupServiceNext function in the client in Microsoft Forefront Threat Management Gateway (TMG) 2010 allows remote attackers to execute arbitrary code via vectors involving unspecified requests, aka "TMG Firewall Client Memory Corruption Vulnerability."

Affected Products

1 product · 1 configurations

Application

forefront threat management gatewaymicrosoft

1 version

2010

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

The NSPLookupServiceNext function in the client in Microsoft Forefront T…

cisa.govCISAMar 2022

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2011-1889 in your stack?

O3 detects CVE-2011-1889 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my stack How O3 SCA works

CVSS Score

9.8/10

CVSS v3 base score

Vector breakdown

AV:Attack Vector

Network

AC:Attack Complexity

Low

PR:Privileges Required

None

UI:User Interaction

None

S:Scope

Unchanged

C:Confidentiality

High

I:Integrity

High

A:Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-119Buffer Overflow

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jun 16, 2011

KEV added

Mar 3, 2022

First exploit

Mar 3, 2022

Last updated

Apr 22, 2026

Identifiers

CVE-2011-1889

References

Advisorysecurityfocus.com Advisorysecuritytracker.com Advisoryexchange.xforce.ibmcloud.com Advisorysecurityfocus.com Advisorysecuritytracker.com Advisoryexchange.xforce.ibmcloud.com Fixdocs.microsoft.com Fixdocs.microsoft.com Websecunia.com Weboval.cisecurity.org Websecunia.com Weboval.cisecurity.org Webcisa.gov

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