CVE-2021-34709 json
Cisco IOS XR Software for Cisco 8000 and Network Convergence System 540 Series Routers Image Verification Vulnerabilities
published 2021-09-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21359
- cvss
- 6.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 4%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- cisco ios_xr 7.3.2, 7.4.1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2 y ago
Exploit prediction
0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.0 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N |
| NVD | 3.1 | 6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.9 | AV:L/AC:M/Au:N/C:C/I:C/A:C |
Affected products
- Cisco Cisco IOS XR Software
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
- Technology feeds
References
Sources
- CVE List CVE-2021-34709
- NVD CVE-2021-34709
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