Executive brief
OpenClaw is a tool that integrates with Feishu (a workplace messaging platform) via webhooks to receive notifications and trigger actions. When configured with only a verification token but not an encryption key, the webhook endpoint would accept forged events from attackers on the network. An attacker could inject fake events, impersonate legitimate senders, and potentially execute downstream actions on connected systems.
Technical details
OpenClaw's Feishu webhook mode failed to enforce cryptographic signature verification when only verificationToken was configured without encryptKey, violating the principle of fail-closed security. The vulnerability stems from improper verification of cryptographic signatures (CWE-347) in the webhook transport layer. An unauthenticated network attacker with network access to the webhook endpoint can craft and inject forged Feishu events by bypassing the incomplete verification logic. This allows event spoofing, sender impersonation, and potential downstream tool execution contingent on local agent policies. The issue is fixed in version 2026.3.12, which now fails closed unless encryptKey is configured and validates all signatures before message dispatch.
Affected products
- OpenClaw OpenClaw <= 2026.3.11
Timeline
- 2026-03-13: disclosed
- 2026-03-12: patched: Fixed in version 2026.3.12
- 2026-03-13: advisory