CVE-2021-1451
Cisco IOS XE Software Easy Virtual Switching System Arbitrary Code Execution Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.1
Cisco IOS XE Software Easy Virtual Switching System Arbitrary Code Execution Vulnerability
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.
- Record
CVE-2021-1451- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
EUVDEUVD-2021-6918
8.1
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.
- Record
EUVD-2021-6918- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-h8m7-5ghv-9r78 No score
A vulnerability in the Easy Virtual Switching System (VSS) feature of Cisco IOS XE Software for...
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.
- Record
GHSA-h8m7-5ghv-9r78- Weakness
- CWE-119
- Updated
- 2026-11-02
NVD
8.1
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.
- Record
CVE-2021-1451- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 9.3 High
AV:N/AC:M/Au:N/C:C/I:C/A:C - Weakness
- CWE-119
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-1451 is a high vulnerability (CVSS 8.1) in Cisco Ios Xe Software, published March 24, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.32%, the 88th percentile. No source names a fixed version.