CVE-2004-1464
MediumExploitedPublic exploitCisco 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.
Published Dec 31, 2004 · Updated Apr 16, 2026
Key Facts
Patch immediately- CVE-2004-1464 is a medium-severity vulnerability (CVSS 5.9 v3.1) affecting IOS (Cisco).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 27, 2006. Public exploit code is available.
- EPSS estimates a 4.8% probability of exploitation in the next 30 days.
- Fixed versions are available, including IOS 12.2\(15\)zj3.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
4.8%
Higher than 91.8% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2004-1464 brief as a PDF
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | May 19, 2023 | Jun 9, 2023 | Not reported |
| Industry KEV feed | Aug 27, 2006 | Jun 9, 2023 | Not reported |
| CIRCL KEV | May 19, 2023 | Jun 9, 2023 | Not reported |
| ENISA EUVD | May 19, 2023 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IOSCisco | See advisory | 12.2\(15\)zj3 |
Patched Releases
IOS
12.2\(15\)zj3
Timeline
Publicly disclosed
Dec 31, 2004
Added to Industry KEV feed
Aug 27, 2006
Added to CISA KEV
May 19, 2023
Added to CIRCL KEV
May 19, 2023
Added to ENISA EUVD
May 19, 2023
Last updated
Apr 16, 2026
Weakness Type
- CWE-400 Uncontrolled Resource Consumption
References
- advisory12395
- advisory1011079
- advisorycisco-ios-telnet-dos(17131)
- advisory20040827 Cisco Telnet Denial of Service Vulnerability
- advisory11060
FAQ
Common Questions.
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.
Affected: IOS (Cisco). The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 27, 2006.
Yes. It was added on May 19, 2023 with a federal remediation due date of Jun 9, 2023.
Public exploit code is available.
Fixed versions are available, including IOS 12.2\(15\)zj3.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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