CVE-2021-1451
No exploitation reported by the sources we read.
- Published2021-03-24
- WeaknessCWE-119
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
A vulnerability in the Easy Virtual Switching System (VSS) feature of Cisco IOS XE Software for Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying Linux operating system of an affected device. The vulnerability is due to incorrect boundary checks of certain values in Easy VSS protocol packets that are destined for an affected device. An attacker could exploit this vulnerability by sending crafted Easy VSS protocol packets to UDP port 5500 while the affected device is in a specific state. When the crafted packet is processed, a buffer overflow condition may occur. A successful exploit could allow the attacker to trigger a denial of service (DoS) condition or execute arbitrary code with root privileges on the underlying Linux operating system of the affected device.
Timeline
dates in UTC- 2021-03-2420:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-1451?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-1451?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 3.6 | = 3.6.0be | no fix published | NVD |
| 3.6 | = 3.6.0e | no fix published | NVD |
| 3.6 | = 3.6.1e | no fix published | NVD |
| 3.6 | = 3.6.2e | no fix published | NVD |
| 3.6 | = 3.6.3e | no fix published | NVD |
| 3.6 | = 3.6.4e | no fix published | NVD |
| 3.6 | = 3.6.5ae | no fix published | NVD |
| 3.6 | = 3.6.5be | no fix published | NVD |
| 3.6 | = 3.6.5e | no fix published | NVD |
| 3.6 | = 3.6.6e | no fix published | NVD |
| 3.6 | = 3.6.7e | no fix published | NVD |
| 3.6 | = 3.6.8e | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
Advisories and patches
- tools.cisco.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-03-24
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-1451?
Is CVE-2021-1451 actively exploited?
What is the CVSS score for CVE-2021-1451?
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