Cisco IOS XR Software for ASR 9000 Series Routers Bidirectional Forwarding Detection Denial of Service Vulnerability

published 2023-03-09 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-24228

cvss: 8.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 64%
public exploits: 0; none known

A vulnerability in the bidirectional forwarding detection (BFD) hardware offload feature of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers, ASR 9902 Compact High-Performance Routers, and ASR 9903 Compact High-Performance Routers could allow an unauthenticated, remote attacker to cause a line card to reset, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of malformed BFD packets that are received on line cards where the BFD hardware offload feature is enabled. An attacker could exploit this vulnerability by sending a crafted IPv4 BFD packet to an affected device. A successful exploit could allow the attacker to cause line card exceptions or a hard reset, resulting in loss of traffic over that line card while the line card reloads.

Patch / fix

fixed in 1

cisco ios_xr 7.5.3, 7.6.2

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 2 y ago (2024-10-28)

Exploit prediction

1.05% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.6	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Cisco Cisco IOS XR Software

Classification

Weakness

CWE-805 Buffer Access with Incorrect Length Value
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

Technology feeds

Cisco IOS rss critical rss

References

sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-bfd-XmRescbT
vendor-advisory

Sources

CVE List CVE-2023-20049
NVD CVE-2023-20049

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary