CVE-2004-1464 — Cisco IOS Denial-of-Service Vulnerability

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2023-05-19. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2005-02-13T05:00:00.000Z
• Last modified: 2025-10-22T00:05:57.162Z
• Added to CISA KEV: 2023-05-19
• BOD 22-01 due: 2023-06-09

09References

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