CVE-2021-1136 - CVE House
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Status published Medium CVE-2021-1136

Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Image Verification Vulnerabilities

Vulnerability Description

Multiple vulnerabilities in Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for the Cisco 8000 Series Routers could allow an authenticated, local attacker to execute unsigned code during the boot process on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

Cisco IOS XR Software
Vulnerable Versions:
Unknown

Timeline

Official Publish: February 4th, 2021
Last Modified: November 8th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)

CWE-347

MITRE ATT&CK TTPs

T1553 Subvert Trust Controls
Defense Evasion
T1190 Exploit Public-Facing Application
Initial Access
T1078 Valid Accounts
Persistence
T1550 Use Alternate Authentication Material
Defense Evasion
T1565 Data Manipulation
Impact