CVE-2023-36846
MEDIUMA Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity.
With a specific request to user.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 SRX 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-S5;
- 22.1 versions
prior to
22.1R3-S3;
- 22.2 versions
prior to
22.2R3-S2;
- 22.3 versions
prior to
22.3R2-S2, 22.3R3;
- 22.4 versions
prior to
22.4R2-S1, 22.4R3.
Affected Products
junosjuniperResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every juniper junos deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the juniper junos security patch or hotfix for CVE-2023-36846 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2023-36846 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2023-36846. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-36846 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2023-36846 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.