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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2023-36847

Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability

KEVMEDIUM 5.3EPSS 85.8%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 November 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to installAppPackage.php that doesn't require authentication an attacker is able to upload arbitrary files via J-Web, leading to a loss of integrity for a certain part of the file system, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on EX Series: * All versions prior to 20.4R3-S8; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
85.77% probability · 100th percentile
CISA KEV
Listed 13 November 2023 · due 17 November 2023
Weakness
CWE-306
Affected
juniper/junos
Source
sirt@juniper.net

CISA notes

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. https://supportportal.juniper.net/s/article/2023-08-Out-of-Cycle-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Multiple-vulnerabilities-in-J-Web-can-be-combined-to-allow-a-preAuth-Remote-Code-Execution?language=en_US; https://nvd.nist.gov/vuln/detail/CVE-2023-36847

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.