CVE-2023-20049

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

HIGH
7.5
CVSS Score
Published: March 9, 2023 at 12:00 AM UTC
Updated: June 17, 2026 at 05:29 AM UTC
13 products affected across 1 vendorIOS XrAsr 9010Asr 9904

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

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.

Affected

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

v < 7.5.37.6 ≤ v < 7.6.27.7
Affected range stops below 7.5.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.6.2, so it looks safe — our inference, not a vendor statement
cisco-asr-9000v-v2 (environment) · cisco-asr-9001 (environment) · cisco-asr-9006 (environment) · cisco-asr-9010 (environment) · cisco-asr-9901 (environment) · cisco-asr-9902 (environment) · cisco-asr-9903 (environment) · cisco-asr-9904 (environment) · cisco-asr-9906 (environment) · cisco-asr-9910 (environment) · cisco-asr-9912 (environment) · cisco-asr-9922 (environment)
All versions
All versions
All versions
All versions
All versions
All versions
All versions
All versions
All versions

Remediation

No guide yet

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

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

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

Quick Info

StatusMODIFIED
CWE
CWE-805CWE-119

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