CVEs / CVE-2023-36844
CVE-2023-36844: Juniper Junos OS EX Series PHP External Variable Modification Vulnerability
- Known exploited in the CISA KEV catalog since 13 Nov 2023
- medium 5.3 CVSS 3.1 (NVD)
- EPSS 89.9% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Juniper Junos OS on EX Series contains a PHP external variable modification vulnerability that 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.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Juniper Networks Junos OS | before 20.4R3-S9 | 20.4R3-S9 |
| Juniper Networks Junos OS | from 21.1, before 21.1* | 21.1* |
| Juniper Networks Junos OS | from 21.2, before 21.2R3-S6 | 21.2R3-S6 |
| Juniper Networks Junos OS | from 21.3, before 21.3R3-S5 | 21.3R3-S5 |
| Juniper Networks Junos OS | from 21.4, before 21.4R3-S5 | 21.4R3-S5 |
| Juniper Networks Junos OS | from 22.1, before 22.1R3-S4 | 22.1R3-S4 |
| Juniper Networks Junos OS | from 22.2, before 22.2R3-S2 | 22.2R3-S2 |
| Juniper Networks Junos OS | from 22.3, before 22.3R3-S1 | 22.3R3-S1 |
| Juniper Networks Junos OS | from 22.4, before 22.4R2-S2, 22.4R3 | 22.4R2-S2, 22.4R3 |
| Juniper Networks Junos OS | from 23.2, before 23.2R1-S1, 23.2R2 | 23.2R1-S1, 23.2R2 |
Exploitation
| In CISA KEV since | 13 Nov 2023 |
|---|---|
| Due date for US federal agencies | 17 Nov 2023 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. |
Severity
| CVSS 3.1 | 5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NScored by NVD |
|---|---|
| Weakness | CWE-473 |
References
- CVE-2023-36844 on NVD
- CVE-2023-36844 in the CISA KEV catalog
- 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 (cited by CISA)
- http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry
- https://supportportal.juniper.net/JSA72300 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36844 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.