How severe is CVE-2023-20233?

CVE-2023-20233 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2023-20233 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-20233?

CVE-2023-20233 primarily affects Cisco Ios Xr. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-20233?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-20233 published?

CVE-2023-20233 was published on 2023-09-13 and last updated on 2026-06-17.

CVE-2023-20233

CVE-2023-20233 is a medium-severity vulnerability in Cisco Ios Xr with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-354.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-354
Affected product: Cisco Ios Xr
Published: 2023-09-13
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2023-20233?: 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.
How severe is CVE-2023-20233?: CVE-2023-20233 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2023-20233 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-20233?: CVE-2023-20233 primarily affects Cisco Ios Xr. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-20233?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-20233 published?: CVE-2023-20233 was published on 2023-09-13 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-xr-cfm-3pWN8MKt

Affected products (2)

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.9.0:*:*:*:*:*:*:*

More vulnerabilities in Cisco Ios Xr

CVE-2020-3284 — Critical (CVSS 9.8): A vulnerability in the enhanced Preboot eXecution Environment (PXE) boot loader for Cisco IOS XR 64-bit Software could…
CVE-2019-1710 — Critical (CVSS 9.8): A vulnerability in the sysadmin virtual machine (VM) on Cisco ASR 9000 Series Aggregation Services Routers running…
CVE-2025-20363 — Critical (CVSS 9.0): A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure…
CVE-2026-20046 — High (CVSS 8.8): A vulnerability in task group assignment for a specific CLI command in Cisco IOS XR Software could allow an…
CVE-2026-20040 — High (CVSS 8.8): A vulnerability in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to execute arbitrary…
CVE-2025-20138 — High (CVSS 8.8): A vulnerability in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to execute arbitrary…

All CVEs affecting Cisco Ios Xr →

Other CWE-354 vulnerabilities

CVE-2025-11543 — Critical (CVSS 9.8): Improper Validation of Integrity Check Value vulnerability in Sharp Display Solutions projectors allows a attacker may…
CVE-2024-25678 — Critical (CVSS 9.8): In LiteSpeed QUIC (LSQUIC) Library before 4.0.4, DCID validation is mishandled.
CVE-2023-33668 — Critical (CVSS 9.8): DigiExam up to v14.0.2 lacks integrity checks for native modules, allowing attackers to access PII and takeover…
CVE-2017-15994 — Critical (CVSS 9.8): rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to…
CVE-2026-49230 — Critical (CVSS 9.1): Improper Validation of Integrity Check Value vulnerability in Apache APISIX. The jwe-decrypt plugin under default…
CVE-2026-34182 — Critical (CVSS 9.1): Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input validation on the…

Browse all CWE-354 vulnerabilities →