Vulnerability identifier: #VU59635

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-31385

CWE-ID: CWE-22

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 user to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in J-Web. A remote low-privileged user can send a specially crafted HTTP request and read arbitrary files on the system.

Successful vulnerability exploitation may allow an attacker to execute arbitrary code with root privileges.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Juniper Junos OS: 19.2 - 19.2R3-S2, 19.2R1-S4, 21.1 - 21.1R1, 20.4 - 20.4R2-S2, 20.1 - 20.1R3, 19.4 - 19.4R3-S4, 19.4R1 - 19.4R1-S4, 19.1 - 19.1R3-S5, 19.1R1-S4, 12.3 - 12.3R12-S18, 19.3 - 19.3R3-S2, 19.3R1-S1, 19.3R2 - 19.3R2-S7, 20.2 - 20.2R3-S1, 18.4 - 18.4R3-S8, 18.4R1-S5, 18.4R2-S3, 15.1 - 15.1R7-S9, 15.1F - 15.1F7-S2, 20.3 - 20.3R2-S1, 18.3 - 18.3R3-S4, 18.3R2-S3, 18.3R3-S1

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External links
http://kb.juniper.net/JSA11253

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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