# CVE-2004-1464: Cisco IOS Denial-of-Service Vulnerability

Source: https://junglewise.ai/threats/cve-2004-1464-cisco-ios-denial-of-service-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-05-19. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2004-1464 · Severity: critical · CVSS 5.9 · Exploited in the wild · Published 2023-05-19

Cisco IOS contains a denial-of-service vulnerability where a crafted TCP connection to the Telnet or reverse Telnet port can exhaust virtual terminal (VTY) connections. This can block legitimate administrative access via Telnet, RSH, SSH, and HTTP.

Technologies: [Cisco IOS](https://junglewise.ai/threats/technologies/ios), [Cisco IOS XE](https://junglewise.ai/threats/technologies/ios-xe), [Cisco IOS XR](https://junglewise.ai/threats/technologies/ios-xr). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2004-1464 exploited in the wild?** Yes. CVE-2004-1464 is known to be exploited in the wild, first recorded on 19 May 2023. Treat it as urgent.

**How severe is CVE-2004-1464?** Critical severity, with a CVSS score of 5.9, published 19 May 2023.

**Which products and versions are affected?** Cisco IOS 12.2(15) and earlier.

**Is there a fix for CVE-2004-1464?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2004-1464 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2004-1464?** Check whether you run Cisco IOS, Cisco IOS XE or Cisco IOS XR. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Cisco IOS 12.2(15) and earlier

## Timeline

- 2004-08-27: disclosed: Initial vendor advisory date based on reference URL
- 2023-05-19: kev added: Added to CISA Known Exploited Vulnerabilities Catalog

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