Microsoft Challenge Handshake Authentication Protocol version 2 (MS-CHAP v2) Information Disclosure Vulnerability

Last Update Date: 22 Aug 2012 12:53 Release Date: 22 Aug 2012 4441 Views

RISK: Medium Risk

TYPE: Operating Systems - Windows OS

Cryptographic weaknesses have been identified in the Microsoft Challenge Handshake Authentication Protocol version 2 (MS-CHAP v2) which could be exploited by attackers to obtain user credentials. Those credentials could then be re-used to authenticate the attacker to network resources, and the attacker could take any action that the user could take on that network resource.

Impact

Information Disclosure

System / Technologies affected

Only VPN solutions that rely on PPTP in combination with MS-CHAP v2 as the sole authentication method are vulnerable to this issue.

Solutions

Before installation of the software, please visit the software manufacturer web-site for more details.

Workarounds:
- Secure your MS-CHAP v2/PPTP based tunnel with PEAP
- Or, as an alternative to implementing PEAP-MS-CHAP v2 Authentication for Microsoft VPNs, use a more secure VPN tunnel
http://technet.microsoft.com/en-us/security/advisory/2743314

Vulnerability Identifier

No CVE information is available

Source

Microsoft