Microsoft .NET Framework CVE-2012-1895 Security Bypass Vulnerability

Description

Microsoft .NET Framework is prone to a security-bypass vulnerability. An attacker can exploit this vulnerability to bypass certain Code Access Security (CAS) restrictions and gain elevated privileges.

Technologies Affected

• Avaya CallPilot 4.0
• Avaya CallPilot 4.0.1
• Avaya CallPilot 5.0
• Avaya CallPilot 5.0.1
• Avaya Communication Server 1000 Telephony Manager 3.0
• Avaya Communication Server 1000 Telephony Manager 3.0.1
• Avaya Communication Server 1000 Telephony Manager 4.0
• Avaya Communication Server 1000 Telephony Manager 4.0.1
• Avaya Conferencing Standard Edition 6.0
• Avaya Conferencing Standard Edition 6.0 SP1
• Avaya Conferencing Standard Edition 6.0.1
• Avaya Meeting Exchange - Client Registration Server 5.0
• Avaya Meeting Exchange - Client Registration Server 5.0.1
• Avaya Meeting Exchange - Client Registration Server 5.2
• Avaya Meeting Exchange - Client Registration Server 5.2.1
• Avaya Meeting Exchange - Recording Server 5.0
• Avaya Meeting Exchange - Recording Server 5.0.1
• Avaya Meeting Exchange - Recording Server 5.2
• Avaya Meeting Exchange - Recording Server 5.2.1
• Avaya Meeting Exchange - Streaming Server 5.0
• Avaya Meeting Exchange - Streaming Server 5.0
• Avaya Meeting Exchange - Streaming Server 5.0.1
• Avaya Meeting Exchange - Streaming Server 5.2
• Avaya Meeting Exchange - Streaming Server 5.2.1
• Avaya Meeting Exchange - Web Conferencing Server 5.0
• Avaya Meeting Exchange - Web Conferencing Server 5.0.1
• Avaya Meeting Exchange - Web Conferencing Server 5.2
• Avaya Meeting Exchange - Web Conferencing Server 5.2.1
• Avaya Meeting Exchange - Webportal 5.0
• Avaya Meeting Exchange - Webportal 5.0.1
• Avaya Meeting Exchange - Webportal 5.2
• Avaya Meeting Exchange - Webportal 5.2.1
• Avaya Messaging Application Server 5.0
• Avaya Messaging Application Server 5.0.1
• Avaya Messaging Application Server 5.2
• Avaya Messaging Application Server 5.2.1
• Microsoft .NET Framework 1.0 SP3
• Microsoft .NET Framework 1.1 SP1
• Microsoft .NET Framework 2.0 SP2
• Microsoft .NET Framework 3.5.1
• Microsoft .NET Framework 4.0

Recommendations

Block external access at the network boundary, unless external parties require service.
If global access isn’t needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of successful exploits.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review its logs regularly.

Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.

Do not follow links provided by unknown or untrusted sources.
To reduce the likelihood of successful exploits, never visit sites of questionable integrity or follow links provided by unfamiliar or untrusted sources.

Vendor updates are available. Please see the references for more information.