CVE-2025-34072

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-34072", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2025-04-15T19:15:22.550Z", "datePublished": "2025-07-02T13:46:31.554Z", "dateUpdated": "2025-07-02T20:29:17.261Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "modules": ["Anthropic Slack MCP Server", "Message content (post/reply body)"], "product": "Slack MCP Server", "vendor": "Anthropic", "versions": [{"status": "affected", "version": "0"}]}], "credits": [{"lang": "en", "type": "finder", "value": "wunderwuzzi of Embrace The Red"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "A data exfiltration vulnerability exists in Anthropic\u2019s 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\u2019s link preview bots (e.g., <code>Slack-LinkExpanding</code>, <code>Slackbot</code>, <code>Slack-ImgProxy</code>) will then issue outbound requests to the attacker-controlled URL, resulting in zero-click exfiltration of private data."}], "value": "A data exfiltration vulnerability exists in Anthropic\u2019s 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\u2019s 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."}], "impacts": [{"capecId": "CAPEC-34", "descriptions": [{"lang": "en", "value": "CAPEC-34 HTTP Response Splitting"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 9.3, "baseSeverity": "CRITICAL", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "HIGH", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-200", "description": "CWE-200 Exposure of Sensitive Information to an Unauthorized Actor", "lang": "en", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-20", "description": "CWE-20 Improper Input Validation", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2025-07-02T13:46:31.554Z"}, "references": [{"tags": ["third-party-advisory", "technical-description", "exploit"], "url": "https://embracethered.com/blog/posts/2025/security-advisory-anthropic-slack-mcp-server-data-leakage/"}, {"tags": ["third-party-advisory"], "url": "https://vulncheck.com/advisories/anthropic-slack-mcp-server-data-exfiltration"}], "source": {"discovery": "UNKNOWN"}, "title": "Anthropic Slack MCP Server Data Exfiltration via Link Unfurling", "x_generator": {"engine": "Vulnogram 0.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2025-07-02T20:29:08.961760Z", "id": "CVE-2025-34072", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-07-02T20:29:17.261Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2025-34072", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2025-07-02T20:29:08.961760Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-07-02T20:29:13.541Z"}}], "cna": {"title": "Anthropic Slack MCP Server Data Exfiltration via Link Unfurling", "source": {"discovery": "UNKNOWN"}, "credits": [{"lang": "en", "type": "finder", "value": "wunderwuzzi of Embrace The Red"}], "impacts": [{"capecId": "CAPEC-34", "descriptions": [{"lang": "en", "value": "CAPEC-34 HTTP Response Splitting"}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "subAvailabilityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "Anthropic", "modules": ["Anthropic Slack MCP Server", "Message content (post/reply body)"], "product": "Slack MCP Server", "versions": [{"status": "affected", "version": "0"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://embracethered.com/blog/posts/2025/security-advisory-anthropic-slack-mcp-server-data-leakage/", "tags": ["third-party-advisory", "technical-description", "exploit"]}, {"url": "https://vulncheck.com/advisories/anthropic-slack-mcp-server-data-exfiltration", "tags": ["third-party-advisory"]}], "x_generator": {"engine": "Vulnogram 0.2.0"}, "descriptions": [{"lang": "en", "value": "A data exfiltration vulnerability exists in Anthropic\u2019s 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\u2019s 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.", "supportingMedia": [{"type": "text/html", "value": "A data exfiltration vulnerability exists in Anthropic\u2019s 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\u2019s link preview bots (e.g., <code>Slack-LinkExpanding</code>, <code>Slackbot</code>, <code>Slack-ImgProxy</code>) will then issue outbound requests to the attacker-controlled URL, resulting in zero-click exfiltration of private data.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-200", "description": "CWE-200 Exposure of Sensitive Information to an Unauthorized Actor"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-20", "description": "CWE-20 Improper Input Validation"}]}], "providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2025-07-02T13:46:31.554Z"}}}, "cveMetadata": {"cveId": "CVE-2025-34072", "state": "PUBLISHED", "dateUpdated": "2025-07-02T20:29:17.261Z", "dateReserved": "2025-04-15T19:15:22.550Z", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "datePublished": "2025-07-02T13:46:31.554Z", "assignerShortName": "VulnCheck"}, "dataVersion": "5.1"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "modules": ["Anthropic Slack MCP Server", "Message content (post/reply body)"], "product": "Slack MCP Server", "vendor": "Anthropic", "versions": [{"status": "affected", "version": "0"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A data exfiltration vulnerability exists in Anthropic\u2019s 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\u2019s 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."}, {"lang": "es", "value": "Existe una vulnerabilidad de exfiltraci\u00f3n de datos en el servidor obsoleto del Protocolo de Contexto de Modelo (MCP) de Slack de Anthropic mediante el despliegue autom\u00e1tico de enlaces. Cuando un agente de IA que utiliza el servidor MCP de Slack procesa datos no confiables, estos pueden manipularse para generar mensajes con hiperv\u00ednculos manipulados por el atacante que integran datos confidenciales. Los bots de previsualizaci\u00f3n de enlaces de Slack (p. ej., Slack-LinkExpanding, Slackbot, Slack-ImgProxy) emiten solicitudes salientes a la URL controlada por el atacante, lo que resulta en la exfiltraci\u00f3n de datos privados sin necesidad de hacer clic."}], "id": "CVE-2025-34072", "lastModified": "2026-06-17T09:13:25.430", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.3, "baseSeverity": "CRITICAL", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "HIGH", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-34072", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2025-07-02T20:29:08.961760Z", "version": "2.0.3"}}]}, "published": "2025-07-02T14:15:24.817", "references": [{"source": "disclosure@vulncheck.com", "url": "https://embracethered.com/blog/posts/2025/security-advisory-anthropic-slack-mcp-server-data-leakage/"}, {"source": "disclosure@vulncheck.com", "url": "https://vulncheck.com/advisories/anthropic-slack-mcp-server-data-exfiltration"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-200"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{}