github - ghsa-gmx5-crwh-6vxg

GHSA-GMX5-CRWH-6VXG

Vulnerability from github – Published: 2025-07-02 15:30 – Updated: 2025-07-02 15:30

Details

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.

Severity ?

9.3 (Critical)


                  
                    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

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{
  "affected": [],
  "aliases": [
    "CVE-2025-34072"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-07-02T14:15:24Z",
    "severity": "CRITICAL"
  },
  "details": "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.",
  "id": "GHSA-gmx5-crwh-6vxg",
  "modified": "2025-07-02T15:30:38Z",
  "published": "2025-07-02T15:30:38Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-34072"
    },
    {
      "type": "WEB",
      "url": "https://embracethered.com/blog/posts/2025/security-advisory-anthropic-slack-mcp-server-data-leakage"
    },
    {
      "type": "WEB",
      "url": "https://vulncheck.com/advisories/anthropic-slack-mcp-server-data-exfiltration"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2025-34072 (GCVE-0-2025-34072)

Vulnerability from cvelistv5 – Published: 2025-07-02 13:46 – Updated: 2025-07-02 20:29

Summary

Severity ?

9.3 (Critical)


                        
                          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

CWE

CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
CWE-20 - Improper Input Validation

Assigner

VulnCheck

References

URL

Tags

	https://embracethered.com/blog/posts/2025/securit…	third-party-advisorytechnical-descriptionexploit
	https://vulncheck.com/advisories/anthropic-slack-…	third-party-advisory

Impacted products

	Vendor	Product	Version
	Anthropic	Slack MCP Server	Affected: 0

Credits

wunderwuzzi of Embrace The Red

Show details on NVD website

JSON

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  "containers": {
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                "id": "CVE-2025-34072",
                "options": [
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                  },
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                "role": "CISA Coordinator",
                "timestamp": "2025-07-02T20:29:08.961760Z",
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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-GMX5-CRWH-6VXG

CVE-2025-34072 (GCVE-0-2025-34072)

Tags

Sightings

Nomenclature