FreeRADIUS: Authentication bypass in EAP-MSCHAPv2 module

1. Gentoo Linux Security Advisory

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-dialup/freeradius	< 1.1.1	>= 1.1.1, < 1.0.0	All supported architectures

Related bugreports: #127229

The EAP-MSCHAPv2 module of FreeRADIUS is affected by a validation issue which causes some authentication checks to be bypassed.

2. Impact Information

FreeRADIUS is an open source RADIUS authentication server implementation.

FreeRADIUS suffers from insufficient input validation in the EAP-MSCHAPv2 state machine.

An attacker could cause the server to bypass authentication checks by manipulating the EAP-MSCHAPv2 client state machine.

3. Resolution Information

There is no known workaround at this time.

All FreeRADIUS users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-dialup/freeradius-1.1.1"

4. References

Page updated April 04, 2006

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.