CVE-2023-20049

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Exploit odds

1.0% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-03-09 22:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:29 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.0% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-03-09 22:15 UTC

Last modified

2026-06-17 05:29 UTC

Exploit probability

1.0% · EPSS, next 30 days

Weakness

CWE-805

Record status

Modified

Affected

• Cisco iOS Xr < 7.5.3
• Cisco iOS Xr < 7.6.2
• Cisco iOS Xr 7.7

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-20049.md and follow it. Check whether this project is affected by CVE-2023-20049. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge