Actively exploited in the wild
Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability
Juniper — Junos OS · Listed in the CISA KEV since 2023-11-13. This indicates confirmed attacks in production environments.
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CVE-2023-36847
MediumCVSS 5.3KEVExploitation Probability (EPSS)
Very high risk100th percentile — higher than 100% of all known CVEs
Summary
A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on EX Series allows an unauthenticated attacker to upload arbitrary files via J-Web. This can lead to a loss of integrity for the file system.
Risk Assessment
An attacker could exploit this vulnerability to introduce malicious files, potentially leading to further attacks on the system. Loss of file system integrity can have serious implications for the organization's security.
Recommendation
It is recommended to update Junos OS to a non-vulnerable version and to monitor the system for unauthorized activities. Additional security measures should also be considered to restrict access to critical functions.
Original NVD description (English source)
A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on EX Series 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. This issue affects Juniper Networks Junos OS on EX 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-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3.