CVE-2023-36847: Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability

CISA Known Exploited Vulnerability (KEV)

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.

Required action (CISA)

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Notes

https://supportportal.juniper.net/s/article/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; https://nvd.nist.gov/vuln/detail/CVE-2023-36847

Weakness behind it

CISA records this vulnerability as an instance of CWE-306. From there the chain continues into CAPEC attack patterns and ATT&CK techniques, all inside this corpus.

References

• NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-36847
• KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog