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TI-2023-06842 Aliases CVE-2023-20135GHSA-6v48-qpg5-fj4m

Improper signature verification in Cisco IOS XR Software

Priority LOW 31CWE-347Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-347.

Summary

A vulnerability in Cisco IOS XR Software image verification checks could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. This vulnerability is due to a time-of-check, time-of-use (TOCTOU) race condition when an install query regarding an ISO image is performed during an install operation that uses an ISO image. An attacker could exploit this vulnerability by modifying an ISO image and then carrying out install requests in parallel. A successful exploit could allow the attacker to execute arbitrary code on an affected device.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00093 0th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco IOS XR Software7.5.3; 7.5.2; 7.5.4; 7.7.1; 7.7.2; 7.7.21; 7.8.1; 7.8.2; 7.9.1; 7.9.2—No fix listedCNA
  • Cisco IOS XR Software VendorCisco Affected 7.5.3; 7.5.2; 7.5.4; 7.7.1; 7.7.2; 7.7.21; 7.8.1; 7.8.2; 7.9.1; 7.9.2 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*7.5.2 to before 7.6; 7.7 to before 7.10.1VulnerableCisco
  • cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:* Versions 7.5.2 to before 7.6; 7.7 to before 7.10.1 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-20135
  2. 2026-10-03 Alias added: GHSA-6v48-qpg5-fj4m

References

Advisory 1

  • TI-2020-02680 Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2018-00135 Memory corruption in Cisco IOS, IOS XE, and IOS XR KEVCVSS 3.1HIGH 8.8
  • TI-2020-03113 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities KEVCVSS 3.1HIGH 8.6
  • TI-2020-03110 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability KEVCVSS 3.1HIGH 8.6
  • TI-2018-00142 Memory corruption in Cisco IOS, IOS XE, and IOS XR KEVCVSS 3.1HIGH 8.0
  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
See all 199 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences