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
ObjectMapperabuse, allowing arbitrary class loading, file/URL access (LFI/SSRF primitives) and, with suitable gadget chains, potential remote code execution and system compromise.
| Ruleset | Rule ID | Legacy Rule ID | Description | Previous Action | New Action | Comments |
|---|---|---|---|---|---|---|
| Cloudflare Managed Ruleset | 100892 | JinJava - SSTI - CVE:CVE-2025-59340 | Log | Block | This is a New Detection |
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