CVE-2023-36844
Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variables
Exploited in the wild. In CISA KEV since 2023‑11‑13. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- Juniper Networks Junos OSAffected: < 20.4R3-S9Upgrade to: 20.4R3-S9Affected: ≥ 21.1, < 21.1*Upgrade to: 21.1*Affected: ≥ 21.2, < 21.2R3-S6Upgrade to: 21.2R3-S6Affected: ≥ 21.3, < 21.3R3-S5Upgrade to: 21.3R3-S5 + 8 more branchesStated by: CVE record
- Juniper JunosAffected: < 20.4Upgrade to: 20.4Stated by: NVD
Versions as the sources state them. Full version matrix after sign-in
Coverage timeline
0 publishersAdded to CISA KEV catalog
Sourced from public security reporting — each date is when it was published, not when it happened.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Listed as exploited in the wild since 2023-11-13.
US federal agencies must remediate by 2023-11-17.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Public exploits
2 sources with a proof of concept or module.
Exploit links, PoCs and Metasploit modules after sign-in- EPSS
90% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
The patch came 133 days before any public exploit.
- EPSS band changecritical → highepss band change
- EPSS band changehigh → critical
- EPSS band changehigh → criticalepss band change
- OpenVAS check added
- EPSS band changecritical → high
- Public exploit / PoCsource: github-pocnuclei check added
Affected products
And 1 more affected product. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Scored 5.3 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity LowData modification is possible but limited in scope or consequence
- Availability NoneNo availability impact
Weaknesses
Sources
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