Read the docs
TI-2023-06938 Aliases CVE-2023-20233GHSA-346q-rm44-2j2v

NULL pointer dereference in Cisco IOS XR Software

Priority LOW 29CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.

Summary

A vulnerability in the Connectivity Fault Management (CFM) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect processing of invalid continuity check messages (CCMs). An attacker could exploit this vulnerability by sending crafted CCMs to an affected device. A successful exploit could allow the attacker to cause the CFM service to crash when a user displays information about maintenance end points (MEPs) for peer MEPs on an affected device.

Why it matters now

EPSS 0.00342 27th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco IOS XR Software5.2.0; 5.2.1; 5.2.2; 5.2.4; 5.2.3; 5.2.5; 5.3.0; 5.3.1; 5.3.2; 5.3.3; 5.3.4; 6.1.1; 6.1.2; 6.1.3; 6.1.4; 6.2.1; 6.2.2; 6.2.3; 6.2.25; 6.3.2; 6.3.3; 6.3.15; 6.4.1; 6.4.2; 6.4.3; 6.5.1; 6.5.2; 6.6.2; 6.6.3; 6.6.25; 6.6.4; 7.0.1; 7.0.2; 7.1.1; 7.1.15; 7.1.2; 7.1.3; 6.7.1; 6.7.2; 6.7.3; 6.7.4; 7.2.1; 7.2.2; 7.3.1; 7.3.2; 7.3.3; 7.4.1; 7.4.2; 6.8.1; 6.8.2; 7.5.1; 7.5.3; 7.5.2; 7.6.1; 7.6.2; 7.7.1; 7.7.2; 6.9.1; 6.9.2—No fix listedCNA
  • Cisco IOS XR Software VendorCisco Affected 5.2.0; 5.2.1; 5.2.2; 5.2.4; 5.2.3; 5.2.5; 5.3.0; 5.3.1; 5.3.2; 5.3.3; 5.3.4; 6.1.1; 6.1.2; 6.1.3; 6.1.4; 6.2.1; 6.2.2; 6.2.3; 6.2.25; 6.3.2; 6.3.3; 6.3.15; 6.4.1; 6.4.2; 6.4.3; 6.5.1; 6.5.2; 6.6.2; 6.6.3; 6.6.25; 6.6.4; 7.0.1; 7.0.2; 7.1.1; 7.1.15; 7.1.2; 7.1.3; 6.7.1; 6.7.2; 6.7.3; 6.7.4; 7.2.1; 7.2.2; 7.3.1; 7.3.2; 7.3.3; 7.4.1; 7.4.2; 6.8.1; 6.8.2; 7.5.1; 7.5.3; 7.5.2; 7.6.1; 7.6.2; 7.7.1; 7.7.2; 6.9.1; 6.9.2 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*before 7.5.4; 7.6 to before 7.6.3; 7.7 to before 7.7.21; 7.8 to before 7.8.2VulnerableCisco
cpe:2.3:o:cisco:ios_xr:7.9.0:*:*:*:*:*:*:*7.9.0VulnerableCisco
  • cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:* Versions before 7.5.4; 7.6 to before 7.6.3; 7.7 to before 7.7.21; 7.8 to before 7.8.2 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:ios_xr:7.9.0:*:*:*:*:*:*:* Versions 7.9.0 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-20233
  2. 2026-10-03 Alias added: GHSA-346q-rm44-2j2v

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