CVE-2026-21007 Overview
CVE-2026-21007 is a security bypass vulnerability in Samsung's Device Care application that allows physical attackers to bypass Knox Guard security controls. The vulnerability stems from an improper check for exceptional conditions (CWE-754) within the Device Care component, which fails to properly validate certain edge-case scenarios during Knox Guard enforcement.
Knox Guard is Samsung's enterprise-focused security feature designed to restrict device functionality for leased, financed, or corporate-owned devices. By exploiting this flaw, an attacker with physical access to a device can circumvent these restrictions, potentially enabling unauthorized device use or data access.
Critical Impact
Physical attackers can bypass Knox Guard security restrictions, potentially unlocking enterprise-managed or carrier-locked Samsung devices and compromising device integrity controls.
Affected Products
- Samsung Android 14.0 (all SMR releases prior to SMR Apr-2026 Release 1)
- Samsung Android 15.0 (all SMR releases prior to SMR Apr-2026 Release 1)
- Samsung Android 16.0 (all SMR releases prior to SMR Apr-2026 Release 1)
Discovery Timeline
- April 13, 2026 - CVE-2026-21007 published to NVD
- April 13, 2026 - Last updated in NVD database
Technical Details for CVE-2026-21007
Vulnerability Analysis
The vulnerability exists within the Device Care application, a system utility pre-installed on Samsung Galaxy devices that handles storage optimization, battery management, and security features. Device Care integrates with Knox Guard to enforce enterprise security policies and device restrictions.
The root issue is an improper check for exceptional conditions where the application fails to properly handle specific edge-case inputs or states during the Knox Guard validation process. When triggered, this allows the security enforcement logic to be bypassed entirely.
The physical access requirement limits the attack surface to scenarios where an adversary has direct device access, such as stolen or lost devices, insider threats, or devices in transit. Despite requiring physical proximity, the potential impact is significant as it could enable integrity violations and availability disruptions to Knox Guard's protective mechanisms.
Root Cause
The vulnerability is classified under CWE-754 (Improper Check for Unusual or Exceptional Conditions). The Device Care application does not adequately verify exceptional or unusual conditions that may occur during Knox Guard policy enforcement. This oversight in error handling or state validation allows an attacker to manipulate the device into a state where Knox Guard restrictions are not properly applied.
Attack Vector
Exploitation requires physical access to a vulnerable Samsung device. The attacker must interact directly with the Device Care application or trigger specific device states that exploit the improper exception handling. The attack does not require user interaction or prior authentication, making it accessible to anyone with physical possession of an unpatched device.
The attack flow involves manipulating the device through physical interaction to trigger exceptional conditions that the Device Care application fails to properly validate, resulting in Knox Guard bypass. This could allow unlocking of carrier-locked devices, circumventing enterprise management policies, or accessing devices that should otherwise be restricted.
Detection Methods for CVE-2026-21007
Indicators of Compromise
- Unexpected changes to Knox Guard enrollment status or policy enforcement state
- Device Care application crashes or unexpected restarts correlating with security policy changes
- Knox Guard restrictions becoming disabled without administrator action
- Audit logs showing unauthorized modification of device management settings
Detection Strategies
- Monitor MDM (Mobile Device Management) dashboards for unexpected Knox Guard policy changes or unenrollment events
- Implement device attestation checks to verify Knox Guard integrity on managed devices
- Review Device Care application logs for abnormal exception handling or crash patterns
- Deploy endpoint detection solutions capable of monitoring Samsung Knox security state changes
Monitoring Recommendations
- Configure alerts for Knox Guard status changes in enterprise MDM solutions
- Implement regular device compliance checks for Samsung fleet devices
- Monitor for physical tampering indicators on high-value enterprise devices
- Establish baseline device security states and alert on deviations
How to Mitigate CVE-2026-21007
Immediate Actions Required
- Apply the Samsung SMR Apr-2026 Release 1 security update immediately on all affected devices
- Prioritize patching for enterprise-managed devices with Knox Guard enabled
- Review Knox Guard enrollment status across all managed Samsung devices
- Implement physical security controls to limit unauthorized device access
Patch Information
Samsung has addressed this vulnerability in the SMR Apr-2026 Release 1 security maintenance release. The patch is available through standard Samsung software update channels. Organizations should refer to the Samsung Mobile Security Update bulletin for detailed patch information.
Affected devices include Samsung Android versions 14.0, 15.0, and 16.0 running any SMR release prior to SMR Apr-2026 Release 1. Updates can be applied via Settings > Software update > Download and install, or deployed remotely through enterprise MDM solutions.
Workarounds
- Implement strict physical access controls for devices pending the security update
- Enable additional authentication factors on Knox Guard-protected devices where available
- Consider temporarily restricting device distribution or deployment until patches are applied
- Monitor devices for signs of tampering or unauthorized Knox Guard status changes
# Verify current Samsung security patch level via ADB
adb shell getprop ro.build.version.security_patch
# Check Knox Guard enrollment status
adb shell pm list packages | grep knox
# Verify Device Care version
adb shell dumpsys package com.samsung.android.lool | grep versionName
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
