CVE-2025-21021
📋 TL;DR
This vulnerability allows local privileged attackers to write out-of-bounds memory in the drawing pinpad component of Blockchain Keystore. Attackers with local access and elevated privileges could potentially execute arbitrary code or cause system instability. Only users of Blockchain Keystore versions prior to 1.3.17.2 are affected.
💻 Affected Systems
- Blockchain Keystore
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Privilege escalation leading to full system compromise, arbitrary code execution, or persistent backdoor installation
Likely Case
Application crash, denial of service, or limited privilege escalation within the keystore context
If Mitigated
Minimal impact due to proper access controls and privilege separation limiting local attacker capabilities
🎯 Exploit Status
Requires local privileged access. Exploitation involves manipulating the drawing pinpad component to trigger out-of-bounds write.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.3.17.2
Vendor Advisory: https://security.samsungmobile.com/serviceWeb.smsb?year=2025&month=08
Restart Required: No
Instructions:
1. Update Blockchain Keystore to version 1.3.17.2 via Samsung's software update mechanism. 2. Check for system updates in device settings. 3. Apply any available security updates.
🔧 Temporary Workarounds
Disable or restrict Blockchain Keystore
AndroidTemporarily disable the Blockchain Keystore functionality if not required
Implement strict local access controls
allLimit physical and local administrative access to affected devices
🧯 If You Can't Patch
- Implement strict privilege separation and least privilege principles
- Monitor for suspicious local privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Blockchain Keystore version in device settings or via package manager: 'adb shell dumpsys package com.samsung.android.keystore'Check Version:
adb shell dumpsys package com.samsung.android.keystore | grep versionNameVerify Fix Applied:
Verify Blockchain Keystore version is 1.3.17.2 or higher using the same command📡 Detection & Monitoring
Log Indicators:
- Unexpected crashes of Blockchain Keystore process
- Privilege escalation attempts in system logs
- Memory access violations in kernel logs
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Process:Blockchain Keystore AND (EventID:1000 OR EventID:1001) OR Privilege:Escalation