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.

Published: 2004-12-31 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2004-2621 is rated Low Risk (33.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.75%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2004-2621

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.32% 0.75% +0.42%
2 2025-03-30 0.36% 0.32% -0.04%
3 2025-03-29 — 0.36% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2004-2621

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.0 2.0 MEDIUM
AV:N/AC:H/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 4.9 4.9 [email protected]

Weakness enumeration for CVE-2004-2621

Affected software / configurations for CVE-2004-2621

Vendor Product Version Raw CPE
nortel contivity 2.1.7 cpe:2.3:h:nortel:contivity:2.1.7:*:*:*:*:*:*:*
nortel contivity 3.00 cpe:2.3:h:nortel:contivity:3.00:*:*:*:*:*:*:*
nortel contivity 3.01 cpe:2.3:h:nortel:contivity:3.01:*:*:*:*:*:*:*
nortel contivity 4.91 cpe:2.3:h:nortel:contivity:4.91:*:*:*:*:*:*:*
nortel contivity 5.01 cpe:2.3:h:nortel:contivity:5.01:*:*:*:*:*:*:*

References for CVE-2004-2621

cvelogic Threat Intelligence