CVE-2023-36851mediumunder attackCWE-306

CVE-2023-36851: medium-severity vulnerability in Juniper Networks Junos OS

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

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43Vexday Risk Score

Prioritize patching. It under exploitation confirmed by CISA.

ssvc Attendcvss 5.3epss 1.1%
from disclosure to weapon
Published on NVDSep 26
CISA KEV+48d
Action required by CISAfederal deadline: 2023-11-17

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

In short

J-Web, a management interface in Juniper SRX firewalls, allows anyone on the network to upload and download files without logging in. This could let attackers steal data or modify system files.

Technical detail

A missing authentication vulnerability in the webauth_operation.php endpoint of Junos OS J-Web on SRX Series allows unauthenticated network-based attackers to upload and download arbitrary files, compromising file system integrity and confidentiality. This can be chained with other vulnerabilities to achieve further compromise.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
Juniper Networks · Junos OS
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CVE-2023-36845CRITICALJunos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to control an important environment variableEPSS 95.1%KEVCVE-2023-36846MEDIUMJunos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesEPSS 93.5%KEVCVE-2023-36844MEDIUMJunos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesEPSS 90.0%KEVCVE-2023-36847MEDIUMJunos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesEPSS 83.5%KEVCVE-2020-1631HIGHOut of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) servicesEPSS 4.9%KEVCVE-2025-21590MEDIUMJunos OS: An local attacker with shell access can execute arbitrary codeEPSS 1.7%KEV