Vulnerability identifier: #VU73203

Vulnerability risk: High

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-20049

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco IOS XR
Operating systems & Components / Operating system
Cisco ASR 9000 Series Aggregation Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
ASR 9902 Compact High-Performance Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
ASR 9903 Compact High-Performance Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to the incorrect handling of malformed BFD packets that are received on line cards where the bidirectional forwarding detection (BFD) hardware offload feature is enabled. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XR: 6.5 - 7.7.0

Cisco ASR 9000 Series Aggregation Services Routers: All versions

ASR 9902 Compact High-Performance Routers: All versions

ASR 9903 Compact High-Performance Routers: All versions

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bfd-XmRescbT

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.