External risk intelligence

Microsoft TMG Firewall Client Code Execution Vulnerability

CVE advisoryKnown Exploit

CVE-2011-1889

Microsoft Forefront Threat Management Gateway 2010 client software is affected by a memory corruption vulnerability. This could allow attackers to execute arbitrary code, posing a risk to system integrity and data. Affected organizations face potential unauthorized access and control of compromised systems.

1Halo Surface Signal

Memory Corruption

Microsoft Forefront Threat Management Gateway

2010

External exposure likelihood

Halo Surface Signal score for CVE-2011-1889

The vulnerability affects the TMG Firewall Client software installed on local endpoints, not the TMG server or gateway appliance itself. Client-side software installed on internal workstations or servers is not designed to be public-internet-facing, making remote exploitation of this specific client-side component via the internet highly unlikely in typical deployments.

Horizon Alert

Summary of the vulnerability and why it matters

Microsoft Forefront Threat Management Gateway (TMG) 2010 contains a flaw within its client component that could permit attackers to execute arbitrary code. This vulnerability stems from an unspecified request processing error within the NSPLookupServiceNext function. If exploited, this could allow for the execution of malicious code within the context of the client application. This raises concerns about potential unauthorized actions and data compromise on affected systems.

  • Vulnerable component: TMG client software
  • Core weakness: Memory corruption vulnerability
  • Main business impact: Arbitrary code execution

Attack Path

How an attacker could exploit the issue

The attack begins when an attacker sends specially crafted requests to the Microsoft Forefront Threat Management Gateway 2010 client. This can lead to a memory corruption vulnerability within the NSPLookupServiceNext function. Successful exploitation allows an attacker to execute arbitrary code on the affected system. This can result in unauthorized control over the compromised system, potentially impacting business operations and data integrity.

  • Unspecified requests to TMG client.
  • Attacker triggers memory corruption.
  • Arbitrary code execution results.

Live Threat

Current exploitation, exposure, and threat context

A critical vulnerability exists within Microsoft Forefront Threat Management Gateway 2010. This issue could allow attackers to execute arbitrary code remotely by exploiting unspecified requests through the TMG Firewall Client. The potential impact is severe, affecting the confidentiality, integrity, and availability of affected systems. Organizations should prioritize addressing this vulnerability due to its exploitable nature and the significant risks it presents.

  • Attackers with low skill could exploit.
  • No special access or conditions needed.
  • Business risk is critical; treat as urgent.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

An organization should address this vulnerability by identifying all instances of the affected software and reducing potential exposure. The vendor has provided updates to fix this issue, and validating that these fixes have been successfully applied is a critical step. Continuous monitoring for related security events is also recommended to ensure ongoing protection.

  • Find all affected systems.
  • Limit network access to affected systems.
  • Apply vendor fix and verify.
  • Monitor for related activity.

Frequently asked questions

What is Microsoft Forefront Threat Management Gateway (TMG) 2010?

Microsoft Forefront Threat Management Gateway (TMG) 2010 is a network security solution that provides firewall and web filtering capabilities. It's used to protect an organization's network from various threats and control internet access for users.

What kind of weakness does CVE-2011-1889 represent?

CVE-2011-1889 is a memory corruption vulnerability, specifically identified as CWE-119. This type of weakness can allow an attacker to overwrite memory in unintended ways, potentially leading to the execution of malicious code.

How is the CVE-2011-1889 vulnerability triggered?

This vulnerability is triggered when an attacker sends specially crafted, unspecified requests to the TMG Firewall Client. Successful exploitation allows an attacker to execute arbitrary code on the affected system. The vulnerability is not triggered by normal or expected requests.

Who should be concerned about CVE-2011-1889?

Organizations using Microsoft Forefront Threat Management Gateway 2010 should be concerned. The Halo Surface Signal indicates this vulnerability affects client software installed on local endpoints, which is typically internal and not directly internet-facing, making remote exploitation via the internet less likely in standard configurations.

What are the first steps to address CVE-2011-1889?

Organizations running affected software should first identify all instances of Microsoft Forefront Threat Management Gateway 2010 client software. Then, they should apply the vendor-provided updates to correct the vulnerability and verify that these fixes have been successfully implemented.

References