2026-06-12 · view entry permalink →
Imperva and Varonis: indirect prompt injection and "agent phishing" against the OpenClaw AI agent, fixed in v2026.4.23, but the attack class generalises
Two independent teams published complementary findings against OpenClaw, the self-hosted AI-agent platform that plugs into messaging systems, mailboxes, file systems and APIs. Imperva showed that shared contact names, vCard fields and location-pin labels flow into the LLM prompt with no untrusted-content boundary: a crafted contact (its injected command hidden behind 65 whitespace characters so the UI truncates it) executed python3 on the victim's host the moment the victim shared the contact with their agent (Imperva, 2026-06-10). Varonis demonstrated "agent phishing": a plain email from a plausible sender persuaded a mailbox-connected agent to forward mock AWS IAM keys and a customer export to an external address, with no exploit involved; the agent simply lacks sender-identity verification before acting (Varonis, 2026-06-09). Both teams note OpenClaw's default memory persistence lets one successful injection survive across sessions. The vendor fix (v2026.4.23) moves messaging-object metadata into a separate untrusted channel, but the structural lesson stands: wherever an agent ingests third-party-controlled strings (contacts, calendar invites, ticket bodies), that channel is an injection surface (T1059). Defender takeaway: pin OpenClaw ≥ v2026.4.23; inventory which AI agents hold mailbox send-permissions or shell access; gate agent-initiated outbound actions behind approval workflows the same way you gate privileged operations.