#VU57437 Out-of-bounds write in Juniper Junos OS and Junos OS Evolved - CVE-2021-31354

Vulnerability identifier: #VU57437

Vulnerability risk: Low

CVSSv4.0: 5.2 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-31354

CWE-ID: CWE-787

Exploitation vector: Local network

Exploit availability: No

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

Vendor: Juniper Networks, Inc.

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error in the handling of responses by a Juniper Agile License (JAL) Client. A remote attacker on the local network can trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 19.2R1-S1 - 19.2R3, 19.3R1-S1 - 19.3R3, 20.1R2-S1 - 20.1R3, 20.2R1-S1 - 20.2R3, 20.3R1-S1 - 20.3R2, 20.4R1-S1 - 20.4R2, 21.1R1-S1 - 21.1R1

Junos OS Evolved: 20.1R1-EVO

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External links
https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11219&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 local network (LAN).

Is there known malware, which exploits this vulnerability?

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