CVE-2023-20233

MEDIUM

6.5

CVSS Score

Published: September 13, 2023 at 04:40 PM UTC

Updated: June 17, 2026 at 05:29 AM UTC

1 product affected across 1 vendorIOS Xr

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.3%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

IOS Xr · Cisco

95%

v < 7.5.47.6 ≤ v < 7.6.37.7 ≤ v < 7.7.217.8 ≤ v < 7.8.25.2.0 5.2.1 5.2.2 5.2.3 5.2.4 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 6.2.25 6.2.3 6.3.15 6.3.2 6.3.3 6.4.1 6.4.2 6.4.3 6.5.1 6.5.2 6.6.2 6.6.25 6.6.3 6.6.4 6.7.1 6.7.2 6.7.3 6.7.4 6.8.1 6.8.2 6.9.1 6.9.2 7.0.1 7.0.2 7.1.1 7.1.15 7.1.2 7.1.3 7.2.1 7.2.2 7.3.1 7.3.2 7.3.3 7.4.1 7.4.2 7.5.1 7.5.2 7.5.3 7.6.1 7.6.2 7.7.1 7.7.2 7.9.0

Affected range stops below 7.5.4, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.6.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.7.21, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.8.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

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

References (1)

Vendor Advisory

Source: [email protected]

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

CVSS

6.5MEDIUM[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: REQUIRED
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-476CWE-354

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