#VU82106 Improper handling of exceptional conditions in Junos OS Evolved and Juniper Junos OS - CVE-2023-44186

Vulnerability identifier: #VU82106

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-44186

CWE-ID: CWE-755

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Junos OS Evolved
Operating systems & Components / Operating system
Juniper Junos OS
Operating systems & Components / Operating system

Vendor: Juniper Networks, Inc.

Description

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

The vulnerability exists due to improper handling of exceptional conditions in AS PATH processing when the router has Non-Stop Routing (NSR) enabled. A remote non-authenticated attacker can send a BGP update message with an AS PATH containing a large number of 4-byte ASes and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Junos OS Evolved: 20.4R1-EVO - 20.4, 21.2-EVO - 21.2R3-S5-EVO, 21.3-EVO - 21.3R3-S4-EVO, 21.4R1-EVO - 21.4R3-S4-EVO, 22.1-EVO - 22.1R3-S3-EVO, 22.2-EVO - 22.2R3-S1-EVO, 22.3R1-EVO - 22.3R2-S1-EVO, 22.4R1-EVO - 22.4R2-EVO, 23.2R1-EVO - 23.2R1-S1-EVO

Juniper Junos OS: 20.4R1-S1 - 20.4, 21.2R1-S1 - 21.2R3, 21.3R1-S1 - 21.3R3, 21.4R1-S1 - 21.4R3, 22.1R1-S1 - 22.1R3, 22.2R1-S1 - 22.2R3, 22.3R1-S1 - 22.3R2, 22.4R1-S1 - 22.4R2, 23.2R1-S1 - 23.2R1

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External links
https://supportportal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-and-Junos-OS-Evolved-RPD-crash-when-attempting-to-send-a-very-long-AS-PATH-to-a-non-4-byte-AS-capable-BGP-neighbor-CVE-2023-44186

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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.