WAF - WAF Release - 2025-10-13

This week’s highlights include a new JinJava rule targeting a sandbox-bypass flaw that could allow malicious template input to escape execution controls. The rule improves detection for unsafe template rendering paths.

Key Findings

New WAF rule deployed for JinJava (CVE-2025-59340) to block a sandbox bypass in the template engine that permits attacker-controlled type construction and arbitrary class instantiation; in vulnerable environments this can escalate to remote code execution and full server compromise.

Impact

• CVE-2025-59340 — Exploitation enables attacker-supplied type descriptors / Jackson ObjectMapper abuse, allowing arbitrary class loading, file/URL access (LFI/SSRF primitives) and, with suitable gadget chains, potential remote code execution and system compromise.

RulesetRule IDLegacy Rule IDDescriptionPrevious ActionNew ActionCommentsCloudflare Managed Ruleset...c04bab5f100892JinJava - SSTI - CVE:CVE-2025-59340LogBlockThis is a New Detection