CVE-2023-36844mediumunder attackCWE-473

CVE-2023-36844: medium-severity vulnerability in Juniper Networks Junos OS

Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variables

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100Vexday Risk Score

Patch now. It under exploitation confirmed by CISA and has a working public exploit.

ssvc Actcvss 5.3epss 90%
from disclosure to weapon8 days
Published on NVDAug 17
1st PoC+8d
CISA KEV+88d
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

A flaw in J-Web (Juniper's web interface) on EX Series switches allows anyone on the network to change important PHP settings without logging in. This could weaken security and potentially be combined with other attacks.

Technical detail

PHP external variable modification vulnerability in J-Web enables unauthenticated network attackers to manipulate critical PHP environment variables via crafted requests. This results in partial integrity loss and may facilitate chaining with additional vulnerabilities on affected Junos OS EX Series versions.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to control certain, important environment variables. Using a crafted request an attacker is able to modify certain PHP environment variables leading to partial loss of integrity, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on EX Series: * All versions prior to 20.4R3-S9; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S7; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S5; * 22.1 versions prior to 22.1R3-S4; * 22.2 versions prior to 22.2R3-S2; * 22.3 versions prior to 22.3R3-S1; * 22.4 versions prior to 22.4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S1, 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-2023-36847MEDIUMJunos 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%KEVCVE-2023-36851MEDIUMJunos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary filesEPSS 1.1%KEV