Emergency WAF rules for critical Cisco RCE vulnerabilities
Cloudflare WAF released emergency protection rules against three critical Cisco vulnerabilities (CVE-2025-20363, CVE-2025-20333, CVE-2025-20362) that enable remote code execution and privilege escalation through improper input validation in HTTP requests. A third detection rule was added on October 7 to complement initial protections deployed September 28.
This week highlights multiple critical Cisco vulnerabilities (CVE-2025-20363, CVE-2025-20333, CVE-2025-20362). This flaw stems from improper input validation in HTTP(S) requests. An authenticated VPN user could send crafted requests to execute code as root, potentially compromising the device. The initial two rules were made available on September 28, with a third rule added today, October 7, for more robust protection.
- Cisco (CVE-2025-20333, CVE-2025-20362, CVE-2025-20363): Multiple vulnerabilities that could allow attackers to exploit unsafe deserialization and input validation flaws. Successful exploitation may result in arbitrary code execution, privilege escalation, or command injection on affected systems.
Impact
Cisco (CVE-2025-20333, CVE-2025-20362, CVE-2025-20363): Exploitation enables attackers to escalate privileges or achieve remote code execution via command injection. Administrators are strongly advised to apply vendor updates immediately.
| Ruleset | Rule ID | Legacy Rule ID | Description | Previous Action | New Action | Comments |
|---|---|---|---|---|---|---|
| Cloudflare Managed Ruleset | ...3a4d1bd6 | 100788B | Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363 | N/A | Block | This is a New Detection |
Source: original entry ↗
More from Cloudflare
Follow Cloudflare to get its new changes in your feed and email digest.
Cloudflare One Client for macOS 2026.8.2100.0
GA release for macOS Cloudflare One Client with improved split tunnel handling that no longer briefly blocks traffic during reconnects, support for non-RFC 1918 local IPv4 networks, faster connects with lower memory use, and numerous reliability fixes across DNS, reauthentication, and client stability.
Cloudflare One Client for Windows 2026.8.2100.0
This GA release improves split tunnel reliability, adds support for non-RFC 1918 local networks, optimizes connection performance with faster reconnections and lower memory usage, and includes numerous bug fixes for DNS, registration, and network handling. The client now features a service recovery mechanism that automatically restarts on system unlock and better handles large hosts files without blocking traffic.
Cloudflare One Client for Linux 2026.8.2100.0
New GA release for Linux with improved split tunnel handling that no longer briefly blocks traffic during reconnects, support for non-RFC 1918 local IPv4 networks, faster tunnel reconnections, and lower memory usage. Includes numerous stability and reliability fixes for DNS, reconnection behavior, and crash issues.