CVE-2023-36847
Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability
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
- 83.45% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 13 November 2023 · due 17 November 2023
- Weakness
- CWE-306
- Affected
- juniper/junos
- Source
- sirt@juniper.net
EPSS moved from 83.5% on 24 September 2026 to 83.5% on 30 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
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
References
- https://supportportal.juniper.net/JSA72300Vendor Advisory
- https://supportportal.juniper.net/JSA72300Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36847US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.