CVE-2023-36847
Published: November 13, 2023
Official Description
Juniper Junos OS on EX Series contains a missing authentication for critical function vulnerability that allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to installAppPackage.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.
CISA KEV Advisory
Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability
Juniper Junos OS on EX Series contains a missing authentication for critical function vulnerability that allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to installAppPackage.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.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Risk Analysis
This vulnerability in Juniper Junos OS on EX Series devices allows an unauthenticated attacker to upload arbitrary files to the file system via the J-Web interface. This can lead to a loss of file system integrity and potentially enable further attacks. The high EPSS score and confirmed exploitation in the wild indicate this is an urgent threat.
Active exploitation of this vulnerability has been observed in the wild, and it is listed in CISA's KEV catalog. The flaw is remotely exploitable without authentication.
Administrators should apply the latest security updates for Juniper Junos OS on EX Series devices. Restricting access to the J-Web interface to trusted networks can also help reduce exposure.
Technical Analysis
CVE-2023-36847 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2023-36847 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2023-36847 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1