CVE-2023-20049 : A vulnerability in the bidirectional forwarding detection (BFD) hardware offload

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.

Published 2023-03-09 22:15:52

Updated 2023-03-16 15:23:43

Source Cisco Systems, Inc.

View at NVD, CVE.org

Vulnerability category: OverflowDenial of service

Products affected by CVE-2023-20049

Cisco » Ios Xr
Versions from including (>=) 7.6 and before (<) 7.6.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Asr 9000v-v2 » Version: N/A
When used together with: Cisco » Asr 9001 » Version: N/A
When used together with: Cisco » Asr 9006 » Version: N/A
When used together with: Cisco » Asr 9010 » Version: N/A
When used together with: Cisco » Asr 9901 » Version: N/A
When used together with: Cisco » Asr 9902 » Version: N/A
When used together with: Cisco » Asr 9903 » Version: N/A
When used together with: Cisco » Asr 9904 » Version: N/A
When used together with: Cisco » Asr 9906 » Version: N/A
When used together with: Cisco » Asr 9910 » Version: N/A
When used together with: Cisco » Asr 9912 » Version: N/A
When used together with: Cisco » Asr 9922 » Version: N/A
Cisco » Ios Xr
Versions before (<) 7.5.3
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Asr 9000v-v2 » Version: N/A
When used together with: Cisco » Asr 9001 » Version: N/A
When used together with: Cisco » Asr 9006 » Version: N/A
When used together with: Cisco » Asr 9010 » Version: N/A
When used together with: Cisco » Asr 9901 » Version: N/A
When used together with: Cisco » Asr 9902 » Version: N/A
When used together with: Cisco » Asr 9903 » Version: N/A
When used together with: Cisco » Asr 9904 » Version: N/A
When used together with: Cisco » Asr 9906 » Version: N/A
When used together with: Cisco » Asr 9910 » Version: N/A
When used together with: Cisco » Asr 9912 » Version: N/A
When used together with: Cisco » Asr 9922 » Version: N/A
Cisco » Ios Xr » Version: 7.7
cpe:2.3:o:cisco:ios_xr:7.7:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Asr 9000v-v2 » Version: N/A
When used together with: Cisco » Asr 9001 » Version: N/A
When used together with: Cisco » Asr 9006 » Version: N/A
When used together with: Cisco » Asr 9010 » Version: N/A
When used together with: Cisco » Asr 9901 » Version: N/A
When used together with: Cisco » Asr 9902 » Version: N/A
When used together with: Cisco » Asr 9903 » Version: N/A
When used together with: Cisco » Asr 9904 » Version: N/A
When used together with: Cisco » Asr 9906 » Version: N/A
When used together with: Cisco » Asr 9910 » Version: N/A
When used together with: Cisco » Asr 9912 » Version: N/A
When used together with: Cisco » Asr 9922 » Version: N/A

Exploit prediction scoring system (EPSS) score for CVE-2023-20049

EPSS FAQ

0.13%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 49 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2023-20049

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
8.6	HIGH	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H	3.9	4.0	Cisco Systems, Inc.
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Changed Confidentiality: None Integrity: None Availability: High
7.5	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	3.9	3.6	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: None Availability: High

CWE ids for CVE-2023-20049

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Assigned by: nvd@nist.gov (Primary)
CWE-805 Buffer Access with Incorrect Length Value

The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.

Assigned by: ykramarz@cisco.com (Secondary)

References for CVE-2023-20049

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bfd-XmRescbT

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

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Vulnerability Details : CVE-2023-20049

Products affected by CVE-2023-20049

Exploit prediction scoring system (EPSS) score for CVE-2023-20049

CVSS scores for CVE-2023-20049

CWE ids for CVE-2023-20049

References for CVE-2023-20049