CVE-2023-36845
Juniper — Juniper Junos OS EX Series and SRX Series PHP External Variable Modification Vulnerability
Juniper · CWE-473 · in CISA KEV since 2023-11-13
EVRS 86 of 100 Immediate
Out-of-Band / Urgent Remediation
Rank 344 of 2,960 tracked
Why it scores 86
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.951.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
- supportportal.juniper.net/…/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
- nvd.nist.gov/…/CVE-2023-36845
Fixed in
junos: update to 20.4 or later
Affected versions
- junos
< 20.420.421.121.221.321.422.122.222.322.423.2 - srx100
- srx110
- srx1400
- srx1500
- srx210
- srx220
- srx240
+21 more affected products; see the full list at NVD.
Remediation
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Fixed versions from NVD.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 9.8 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.951 (99.87th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2023-11-17 · KEV since 2023 · listed over a year | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | Public module exists | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 9.8 (v3.1), assigned by juniper. | Listed | ENISA EUVD |
Description
NVDA PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series and SRX Series allows an unauthenticated, network-based attacker to remotely execute code. Using a crafted request which sets the variable PHPRC an attacker is able to modify the PHP execution environment allowing the injection und execution of code. This issue affects Juniper Networks Junos OS on EX Series and SRX 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 22.3R2-S2, 22.3R3-S1; * 22.4 versions prior to 22.4R2-S1, 22.4R3; * 23.2 versions prior to 23.2R1-S1, 23.2R2.
What CISA says to do
- supportportal.juniper.net/…/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
- nvd.nist.gov/…/CVE-2023-36845
Public module
Metasploit lists a public excellent-rank module for this CVE: Junos OS PHPRC Environment Variable Manipulation RCE (freebsd/http/junos_phprc_auto_prepend_file). A module existing is not the same as active exploitation; see metasploit.com.