[Full-Disclosure] Nortel Networks Contivity VPN Client information leakage vulnerability
From: Network Intelligence (I) Pvt. Ltd. (info_at_nii.co.in)
To: email@example.com, "firstname.lastname@example.org" <email@example.com>, "firstname.lastname@example.org" <email@example.com> Date: Wed, 10 Nov 2004 13:21:08 +0530
Name: User Account Enumeration in Nortel Contivity VPN
Vendor: Nortel Networks
Products Affected: Nortel Networks Contivity VPN Client
Type: Remote User Account Enumeration
The Nortel Networks Contivity VPN Client authentication error message
provides more information than is necessary, thus allowing an attacker
to discover existing users on the system. This bug was discovered as
part of a penetration test we carried out on the VPN server of a client.
1. If a valid user name and an invalid password is given, the Contivity
VPN Client displays "Login Failure due to: authentication failure"
2. If an invalid user name is given, the Contivity VPN Client displays
"Login Failed: Please verify the entered login information is correct".
The different error messages could enable a malicious person to guess
valid user names on the Contivity VPN/Firewall, and then launch
password-guessing attacks against these accounts.
This issue is resolved in Contivity VPN Client for Windows V5.01_030
Refer to the CERT VU Note at
http://www.kb.cert.org/vuls/id/830214 and our full advisory at
for information about vendor response, applying the patches, and other
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