Microsoft .NET Framework XML Digital Signature CVE-2013-1336 Security Bypass Vulnerability

Description

Microsoft .NET Framework is prone to a security-bypass vulnerability because it fails to properly validate the signature of a specially crafted XML file. Attackers can exploit this issue to bypass XML digital signature validation and spoof XML content by conducting man-in-the-middle attacks. Successful exploits will cause victims to accept the spoofed XML files assuming they are legitimate.

Technologies Affected

• Avaya CallPilot 4.0
• Avaya CallPilot 4.0.1
• Avaya CallPilot 5.0
• Avaya CallPilot 5.0.1
• Avaya CallPilot
• Avaya CallPilot Unified Messaging
• 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 Communication Server 1000 Telephony Manager
• 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 - Client Registration Server 6.0
• Avaya Meeting Exchange - Client Registration Server
• Avaya Meeting Exchange - Enterprise Edition
• 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 - Recording Server 6.0
• Avaya Meeting Exchange - Recording Server
• 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 - Streaming Server 6.0
• Avaya Meeting Exchange - Streaming Server
• 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 - Web Conferencing Server 6.0
• Avaya Meeting Exchange - Web Conferencing Server
• 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 Meeting Exchange - Webportal 6.0
• Avaya Meeting Exchange - Webportal
• Avaya Messaging Application Server 4
• Avaya Messaging Application Server 5
• 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
• Avaya Messaging Application Server
• Avaya Messaging Application Server MM 1.1
• Avaya Messaging Application Server MM 2.0
• Avaya Messaging Application Server MM 3.0
• Avaya Messaging Application Server MM 3.1
• Microsoft .NET Framework 2.0 SP2
• Microsoft .NET Framework 3.5
• Microsoft .NET Framework 3.5.1
• Microsoft .NET Framework 4.0
• Microsoft .NET Framework 4.5

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 exploits.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.

Communicate sensitive information through secure means.
Use multiple layers of encryption when communicating sensitive information between a client and a server. This will reduce the chance of a successful exploit.

Updates are available. Please see the references or vendor advisory for more information.