Executive brief
OpenClaw is a web service that fetches content from URLs provided by users. The service has security controls to prevent Server-Side Request Forgery (SSRF) attacks, which could allow attackers to access internal systems. A flaw in these controls allows attackers to bypass private-address filtering by using a specially crafted IPv6 address format (ISATAP) that conceals private IPv4 targets, potentially enabling unauthorized access to internal networks and services.
Technical details
OpenClaw's SSRF hostname/IP guard failed to detect ISATAP (Intra-Site Automatic Tunnel Addressing Protocol) embedded IPv4 addresses in the format ...:5efe:w.x.y.z. An attacker could craft a URL containing an ISATAP IPv6 literal to embed a private IPv4 target (such as loopback 127.0.0.1) and bypass the service's private-address filtering in URL-fetching code paths. The vulnerability requires attacker-controlled input reaching a URL-fetching function. The fix adds RFC 5214 ISATAP embedded-IPv4 detection to the shared SSRF classifier and centralizes hostname/IP blocking through a shared isBlockedHostnameOrIp validator. The vulnerability affects OpenClaw versions 2026.1.20 through 2026.2.17 and is patched in 2026.2.19.
Affected products
- OpenClaw openclaw >=2026.1.20, <=2026.2.17
Timeline
- 2026-03-04: disclosed
- 2026-02-19: patched: Patch released in version 2026.2.19