CVE-2004-1105

Nortel Networks Contivity VPN Client displays a different error message depending on whether the username is valid or invalid, which could allow remote attackers to gain sensitive information.

CVE-2004-2621

Nortel Contivity VPN Client 2.1.7, 3.00, 3.01, 4.91, and 5.01, when opening a VPN tunnel, does not check the gateway certificate until after a dialog box has been displayed to the user, which creates a race condition that allows remote attackers to perform a man-in-the-middle (MITM) attack.