Vulnerability identifier: #VU52231

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-0237

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

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

Vendor: Juniper Networks, Inc.

Description

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

The vulnerability exists due to insufficient validation of user-supplied input when processing specific layer 2 frames on Juniper Networks EX4300-MP Series, EX4600 Series, EX4650 Series, QFX5K Series deployed as a Virtual Chassis with a specific Layer 2 circuit configuration. A remote attacker can send specially crafted traffic to the system and crash the Packet Forwarding Engine manager (FXPC).

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 17.4 - 17.4R3-S3, 17.4R2-S9, 19.4 - 19.4R3, 19.4R1 - 19.4R1-S4, 20.3 - 20.3R1-S1, 20.2 - 20.2R2-S3, 19.1 - 19.1R3-S3, 19.1R1-S4, 17.3 - 17.3R3-S10, 15.1 - 15.1R7-S8, 15.1F - 15.1F7-S2, 20.4, 19.2 - 19.2R3, 19.2R1-S4, 18.4 - 18.4R3-S5, 18.4R1-S5, 18.4R2-S3, 18.3 - 18.3R3-S3, 18.3R2-S3, 18.3R3-S1, 19.3 - 19.3R3, 19.3R1-S1, 19.3R2 - 19.3R2-S7, 20.1 - 20.1R1-S4

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External links
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA11132&cat=SIRT_1&actp=LIST

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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.