CVE-2023-36851 MEDIUM

CVE-2023-36851: Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary files

Vendor Juniper Networks
Product Junos OS
Weakness CWE-306 · Missing auth
KEV Status Known Exploited
Published September 26, 2023
Last update October 21, 2025
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CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.php that doesn't require authentication, an attacker is able to upload and download arbitrary files via J-Web, leading to a loss of integrity or confidentiality, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on SRX Series: * 21.2 versions prior to 21.2R3-S8; * 21.4 versions prior to 21.4R3-S6; * 22.1 versions prior to 22.1R3-S5; * 22.2 versions prior to 22.2R3-S3; * 22.3 versions prior to 22.3R3-S2; * 22.4 versions prior to 22,4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S2, 23.2R2.

CISA mandated remediation

02CISA Required Action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Key dates

03Disclosure timeline

September 26, 2023 CVE published
October 21, 2025 Record updated