CVE-2023-20049
HIGHDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 61% of all known CVEs.
References
Related Vulnerabilities
Other CWE-805 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-14509 | Critical | 9.8 | 2.0% | - | Fix |
| CVE-2025-23319 | High | 8.1 | 1.6% | - | Fix |
| CVE-2024-24851 | High | 7.5 | 1.4% | - | - |
| CVE-2021-31885 | High | 7.5 | 1.2% | - | Fix |
| CVE-2020-16101 | High | 7.5 | 1.0% | - | Fix |
| CVE-2022-0519 | High | 7.1 | 1.0% | - | Fix |
Common questions
How do I fix CVE-2023-20049?
Upgrade ios xr to 7.6.2 or later.
Is CVE-2023-20049 being actively exploited?
Not that we know of. CVE-2023-20049 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 61% of all scored CVEs.
How severe is CVE-2023-20049?
CVE-2023-20049 has a CVSS v3 base score of 8.6, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2023-20049 affect?
Published advisories record a fix for ios xr (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.