Cyber Resilience

CVE-2023-20233

Medium

Published: 13 September 2023

Published
13 September 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS Score 0.0014 34.5th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-20233 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Cisco Ios Xr. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 34.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cisco
ios xr
7.9.0 · ≤ 7.5.4 · 7.6 — 7.6.3 · 7.7 — 7.7.21

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-354

Proper validation of integrity check values is required for reliable tamper detection, directly reducing undetected modification risks.

addresses: CWE-354

Requires validation of integrity check values on every resolution response, directly mitigating tampered or corrupted DNS data.

addresses: CWE-354

Control mandates proper validation of integrity values (checksums) on prepared data, making flawed validation of those checks ineffective for attackers.

addresses: CWE-354

Requires use of proper integrity verification tools, reducing the chance an incorrect check value is accepted.

addresses: CWE-354

Requires proper validation of integrity mechanisms, directly mitigating flawed check-value handling.

References