CVE-2021-25412
📋 TL;DR
This vulnerability allows local attackers to bypass access controls in Samsung's genericssoservice, enabling them to execute protected activities with system privileges via untrusted applications. It affects Samsung mobile devices running vulnerable versions of the software prior to the June 2021 security update.
💻 Affected Systems
- Samsung mobile devices
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker with local access could gain full system-level control over the device, potentially installing persistent malware, accessing sensitive data, or disabling security controls.
Likely Case
Malicious apps could escalate privileges to perform unauthorized actions, access protected system resources, or bypass security restrictions.
If Mitigated
With proper patching, the vulnerability is eliminated, preventing privilege escalation through this vector.
🎯 Exploit Status
Exploitation requires local access and ability to run untrusted applications. The vulnerability is in access control logic, making exploitation relatively straightforward for attackers with local access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: SMR JUN-2021 Release 1 or later
Vendor Advisory: https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=6
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Install the June 2021 security update (SMR JUN-2021 Release 1). 3. Restart the device after installation.
🔧 Temporary Workarounds
Restrict app installations
allPrevent installation of untrusted applications that could exploit this vulnerability
Disable unknown sources
allDisable installation from unknown sources in Android settings
🧯 If You Can't Patch
- Restrict physical access to devices and implement strict app installation policies
- Monitor for suspicious privilege escalation attempts and unusual system activity
🔍 How to Verify
Check if Vulnerable:
Check device security patch level in Settings > About phone > Software information. If patch level is earlier than June 1, 2021, device is vulnerable.Check Version:
Settings > About phone > Software information > Android security patch levelVerify Fix Applied:
Verify security patch level shows 'June 1, 2021' or later in device settings.📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation attempts in system logs
- GenericSSOService access from untrusted applications
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Look for privilege escalation events or unauthorized access to system services from non-system applications