What is CVE-2023-36845?

CVE-2023-36845 is a critical PHP External Variable Modification vulnerability affecting Juniper Networks Junos OS on EX Series and SRX Series devices. This vulnerability allows an unauthenticated, network-based attacker to remotely execute code by modifying the PHP execution environment through a crafted request. The issue impacts a wide range of systems, posing significant risks to affected organizations.

Who is impacted by this?

If you're using Juniper Networks Junos OS on EX Series or SRX Series devices, you might be affected by the CVE-2023-36845 vulnerability. This issue impacts various versions, including all version s before 20.4R3-S9, 21.1R1 and later, 21.2 versions before 21.2R3-S7, 21.3 versions before 21.3R3-S5, 21.4 versions before 21.4R3-S5, 22.1 versions before 22.1R3-S4, 22.2 versions before 22.2R3-S2, 22.3 versions before 22.3R2-S2 and 22.3R3-S1, 22.4 versions before 22.4R2-S1 and 22.4R3, and 23.2 versions before 23.2R1-S1 and 23.2R2. Stay informed and take necessary precautions to protect your systems.

What should I do if I’m affected?

If you're affected by the CVE-2023-36845 vulnerability, it's crucial to take action to secure your systems. Start by upgrading your software to a release that prevents code execution, such as those mentioned in the Juniper Networks Security Bulletin. Additionally, consider applying a workaround by disabling J-Web or limiting access to trusted hosts only. Stay vigilant and keep your systems updated to minimize risks.

Is this in CISA’s Known Exploited Vulnerabilities Catalog?

Yes, the CVE-2023-36845 vulnerability is in CISA's Known Exploited Vulnerabilities Catalog. It is named "Juniper Junos OS EX Series and SRX Series PHP External Variable Modification Vulnerability" and was added on November 13, 2023. The due date for required action is November 17, 2023. To address this vulnerability, apply mitigations as per vendor instructions or discontinue the product's use if mitigations are unavailable.

Weakness Enumeration

The weakness enumeration for this vulnerability is categorized as CWE-473, which involves PHP External Variable Modification issues.

Learn More

For a comprehensive understanding of this vulnerability, consult the National Vulnerability Database and the sources listed below.

• Juniper Networks Security Bulletin

• CISA Binding Operational Directive 22-01