CVE-2021-1136: cisco cisco ios xr software
Vulnerability summary
CVE-2021-1136 is a medium (CVSS 6.7) vulnerability in cisco cisco ios xr software. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.7% of scored vulnerabilities.
Timeline
- 04-02-2021PublishedVulnerability first disclosed.
- 08-11-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST6.7MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
10%
Versus all other CVEs
30-day change
0.00 pp
From 0.20% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Cisco2 products
- cisco ios xr softwaren/a
- ios_xr< 7.0.12 | ≥ 7.1.0, < 7.2.1 | < 7.2.1
1 vendor · 2 products
References
1 links- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ioxr-l-zNhcGCBtVendor AdvisoryX Refsource CISCO