CVE-2023-36844
Juniper Junos OS EX Series PHP External Variable Modification 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 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
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 89.96% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 13 November 2023 · due 17 November 2023
- Weakness
- CWE-473
- Affected
- juniper/junos
- Source
- sirt@juniper.net
EPSS 90.0% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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-2023-36844
References
- http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- https://supportportal.juniper.net/JSA72300Vendor Advisory
- http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- https://supportportal.juniper.net/JSA72300Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36844US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.