High‑Severity Race Condition in Samsung Mobile Devices' MFC Charger Driver (CVE‑2021‑25394)
What It Is
A race‑condition flaw in the Multi‑Function Charger (MFC) driver of Samsung Android devices can trigger a use‑after‑free condition. When an attacker first compromises the device’s radio privilege, the flaw permits an arbitrary memory write, potentially leading to code execution at the kernel level.
Exploitability
- No public proof‑of‑concept has been released, but the vulnerability is classified as High severity by NVD and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, indicating a realistic threat of active exploitation.
- Exploitation requires local access to the radio subsystem (e.g., via a malicious charger or USB‑based attack), making it a privileged escalation vector rather than a remote drive‑by.
Affected Products
- Samsung mobile devices running the affected MFC charger driver (specific model list disclosed by Samsung security advisory).
- Any Android deployment that includes these firmware versions, whether consumer‑owned or enterprise‑managed.
Why It Matters for Compliance & Audit Readiness
- Control Assurance: The flaw bypasses the device’s hardware‑based isolation, undermining the integrity of the underlying operating system. For organizations that rely on mobile device management (MDM) to demonstrate compliance (e.g., ISO 27001, NIST CSF PR.IP‑1 “A vulnerability management program is established and maintained”), evidence of timely patching becomes a critical audit artifact.
- Continuous Monitoring: Detecting the presence of the vulnerable driver version across the device fleet supports a defensible audit trail and satisfies vendor‑management controls that require proof of due diligence.
- Access Controls: Because exploitation hinges on a compromised radio privilege, reinforcing least‑privilege configurations and restricting USB/charging interfaces aligns with access‑control policies (NIST AC‑6).
Recommended Actions
- Patch Management: Deploy Samsung’s security update that resolves CVE‑2021‑25394 to all managed devices. Verify patch status through your MDM console and capture screenshots for audit evidence.
- Device Configuration: Enforce policies that disable USB charging when the device is locked and restrict radio‑privilege‑escalation pathways (e.g., limit carrier‑specific apps).
- Monitoring: Enable logging of charger‑driver load events and anomalous kernel‑memory writes; correlate with SIEM alerts for potential exploitation attempts.
- Documentation: Record remediation dates, affected asset inventory, and control mapping (e.g., PR.IP‑1, AC‑6) in your compliance repository to demonstrate due diligence.
Source: CISA KEV – CVE‑2021‑25394