{"id":"CVE-2021-34708","aliases":["EUVD-2021-21358","GHSA-xw5r-2555-jwfv"],"status":"published","title":"Cisco IOS XR Software for Cisco 8000 and Network Convergence System 540 Series Routers Image Verification Vulnerabilities","description":"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.","severity":{"version":"3.1","score":6,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00183,"percentile":0.07991,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-347"],"published":"2021-09-09T05:00:16Z","modified":"2026-06-17T03:56:23Z","products":[{"vendor":"cisco","product":"cisco ios xr software"},{"vendor":"cisco","product":"ios_xr"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-QN9mCzwn","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34708"},{"url":"https://github.com/advisories/GHSA-xw5r-2555-jwfv"}],"sources":{"cve":[{"id":"CVE-2021-34708","title":"Cisco IOS XR Software for Cisco 8000 and Network Convergence System 540 Series Routers Image Verification Vulnerabilities","description":"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.","status":"published","published":"2021-09-09T05:00:16.036Z","modified":"2024-11-07T22:01:21.744Z","cvss":[{"version":"3.1","score":6,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:33:11.59359Z"}],"euvd":[{"id":"EUVD-2021-21358","description":"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.","status":"published","published":"2021-09-09T05:00:16Z","modified":"2024-11-07T22:01:21Z","cvss":[{"version":"3.1","score":6,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N","level":"medium"}],"updated_at":"2026-11-03T00:05:07.279991Z"}],"ghsa":[{"id":"GHSA-xw5r-2555-jwfv","title":"Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS)...","description":"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.","status":"published","published":"2022-05-24T19:14:07Z","modified":"2023-01-30T05:02:03Z","cwes":["CWE-347"],"updated_at":"2026-11-02T14:46:33.145275Z"}],"nvd":[{"id":"CVE-2021-34708","description":"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.","status":"published","published":"2021-09-09T05:15:07.207Z","modified":"2026-06-17T03:56:23.843Z","cvss":[{"version":"3.1","score":6,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.7,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":7.2,"vector":"AV:L/AC:L/Au:N/C:C/I:C/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:06:58.502206Z"}]}}