Remote code execution in Juniper Networks Junos OS and Junos OS Evolved

1) Out-of-bounds write

EUVDB-ID: #VU57437

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 - Out-of-bounds write

Exploit availability: No

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 - 21.1R1

Junos OS Evolved: 20.1R1-EVO

CPE2.3

• cpe:2.3:o:juniper_networks:juniper_junos_os:19.2R3:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:juniper_junos_os:19.3R3:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:juniper_junos_os:20.1R3:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:juniper_junos_os:20.2R3:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:juniper_junos_os:20.3R2:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:juniper_junos_os:20.4R2:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:juniper_junos_os:21.1R1:*:*:*:*:*:*:*
• cpe:2.3:o:juniper_networks:junos_os_evolved:20.1R1-EVO:*:*:*:*:*:*:*

External links

https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11219&cat=SIRT_1&actp=LIST

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.