CVE-2021-34708
Cisco IOS XR Software for Cisco 8000 and Network Convergence System 540 Series Routers Image Verification Vulnerabilities
Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Cisco IOS XR Software for Cisco 8000 and Network Convergence System 540 Series Routers Image Verification Vulnerabilities
Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.
- Record
CVE-2021-34708- CVSS 3.1
- 6.0 Medium
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-02
EUVDEUVD-2021-21358
Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.
- Record
EUVD-2021-21358- CVSS 3.1
- 6.0 Medium
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xw5r-2555-jwfvNo score
Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS)...
Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.
- Record
GHSA-xw5r-2555-jwfv- Weakness
- CWE-347
- Updated
- 2026-11-02
NVD
Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.
- Record
CVE-2021-34708- CVSS 3.1
- 6.0 Medium
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N - CVSS 3.1
- 6.7 Medium
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.2 High
AV:L/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-347
- 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-2021-34708 is a medium vulnerability (CVSS 6.0) in Cisco Ios Xr Software, published September 9, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.18%, the 7th percentile. No source names a fixed version.