oasis.securitywriteupAI Security Briefing
Oasis Security details "PromptFiction," a vulnerability in Claude Desktop's registered claude:// URL scheme that lets a single clicked link auto-submit an attacker-controlled prompt to the app with no user confirmation. Their PoC used a fake ASCII-art tool link that carried a visible request plus a hidden instruction, and the same channel could be abused to plant hidden prompts, exfiltrate conversation history, read the filesystem, or execute code. Anthropic fixed the issue in Claude Desktop 1.1.2321.
TL;DR Claude Desktop's claude:// URL scheme allowed one-click, unconfirmed prompt injection until it was patched in version 1.1.2321.
Organisations named here
- PromptFiction
Technologies named here
- Claude Desktop
- PromptFiction
Techniques named here
- claude:// URL scheme prompt injection
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