A data exfiltration vulnerability exists in Anthropic’s deprecated Slack Model Context Protocol (MCP) Server via automatic link unfurling. When an AI agent using the Slack MCP Server processes untrusted data, it can be manipulated to generate messages containing attacker-crafted hyperlinks embedding sensitive data. Slack’s link preview bots (e.g., Slack-LinkExpanding, Slackbot, Slack-ImgProxy) will then issue outbound requests to the attacker-controlled URL, resulting in zero-click exfiltration of private data.
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Wed, 02 Jul 2025 21:15:00 +0000
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Wed, 02 Jul 2025 14:00:00 +0000
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Description | A data exfiltration vulnerability exists in Anthropic’s deprecated Slack Model Context Protocol (MCP) Server via automatic link unfurling. When an AI agent using the Slack MCP Server processes untrusted data, it can be manipulated to generate messages containing attacker-crafted hyperlinks embedding sensitive data. Slack’s link preview bots (e.g., Slack-LinkExpanding, Slackbot, Slack-ImgProxy) will then issue outbound requests to the attacker-controlled URL, resulting in zero-click exfiltration of private data. | |
Title | Anthropic Slack MCP Server Data Exfiltration via Link Unfurling | |
Weaknesses | CWE-20 CWE-200 |
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cvssV4_0
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Status: PUBLISHED
Assigner: VulnCheck
Published: 2025-07-02T13:46:31.554Z
Updated: 2025-07-02T20:29:17.261Z
Reserved: 2025-04-15T19:15:22.550Z
Link: CVE-2025-34072

Updated: 2025-07-02T20:29:13.541Z

Status : Awaiting Analysis
Published: 2025-07-02T14:15:24.817
Modified: 2025-07-03T15:13:53.147
Link: CVE-2025-34072

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