CVE-2024-44093 Overview
CVE-2024-44093 is a high-severity memory corruption vulnerability in Google Android. The flaw resides in the ppmp_unprotect_buf function of drm/code/drm_fw.c, part of the Digital Rights Management (DRM) framework. A logic error in this function allows local memory corruption that can lead to privilege escalation. Exploitation requires no user interaction and no additional execution privileges beyond a local, low-privileged context. Google addressed the issue in the September 2024 Android Security Bulletin. The vulnerability is classified under CWE-787 (Out-of-Bounds Write) and CWE-783 (Operator Precedence Logic Error).
Critical Impact
A local attacker with low privileges can trigger memory corruption in the Android DRM driver to escalate privileges without user interaction.
Affected Products
- Google Android (see Android Security Bulletin September 2024 for exact versions)
- Pixel devices covered by the September 2024 Pixel bulletin
- Devices integrating the affected drm_fw kernel component
Discovery Timeline
- 2024-09-13 - CVE-2024-44093 published to NVD
- 2024-09-01 - Google publishes fix in the Android Security Bulletin (September 2024)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-44093
Vulnerability Analysis
The vulnerability exists in ppmp_unprotect_buf, a routine in drm/code/drm_fw.c that handles unprotecting memory buffers within the Android DRM framework. A logic error in the buffer state handling permits an out-of-bounds write during buffer unprotection. The DRM framework operates with elevated kernel privileges, so corrupting its internal state impacts the confidentiality, integrity, and availability of the entire device.
An attacker who runs a local, unprivileged application on the device can invoke the affected code path through the DRM interface. Successful exploitation yields kernel-level code execution or privilege escalation to a system context. Because the flaw is a logic error rather than a race or timing condition, exploitation is deterministic once the attacker controls input to the vulnerable path.
Root Cause
The root cause is a logic error in the buffer unprotect routine. The function fails to correctly validate buffer state or index boundaries before performing a write operation, aligning with the [CWE-787] out-of-bounds write and [CWE-783] operator precedence weaknesses assigned by MITRE. As a result, an attacker-controlled condition causes the driver to write outside the intended memory region.
Attack Vector
The attack vector is local. An attacker requires the ability to execute a low-privileged application on the target Android device, which can be achieved through a malicious app installation or chained exploitation from a lower-privileged component. Once resident, the attacker interacts with the DRM subsystem to trigger ppmp_unprotect_buf under conditions that produce the memory corruption. User interaction is not required.
No public proof-of-concept exploit is currently listed for CVE-2024-44093, and the vulnerability is not present on the CISA Known Exploited Vulnerabilities list.
Detection Methods for CVE-2024-44093
Indicators of Compromise
- Unexpected kernel panics or crashes referencing the drm_fw module or ppmp_unprotect_buf in logcat and dmesg output.
- Newly installed applications performing repeated ioctl calls against DRM device nodes such as /dev/drm_fw or vendor-specific DRM endpoints.
- Processes transitioning from an untrusted app context to system or root without a corresponding legitimate authorization event.
Detection Strategies
- Monitor Android bug reports and kernel logs for repeated faults inside the DRM buffer management routines.
- Inspect installed applications for use of DRM ioctl interfaces inconsistent with the app's declared functionality.
- Correlate abnormal SELinux denials that reference DRM device nodes with subsequent privilege changes.
Monitoring Recommendations
- Deploy Mobile Threat Defense on managed Android fleets and forward device telemetry, including patch level, to a centralized SIEM.
- Track the ro.build.version.security_patch property across the fleet to confirm devices are on the September 2024 patch level or later.
- Alert on devices reporting a security patch level older than 2024-09-01.
How to Mitigate CVE-2024-44093
Immediate Actions Required
- Apply the September 2024 Android security patch level (2024-09-01 or later) on all managed Android devices.
- Prioritize Pixel devices and OEM builds that ship the affected drm_fw kernel driver.
- Restrict installation of applications from untrusted sources through enterprise mobility management (EMM) policy.
- Audit installed applications requesting access to DRM interfaces and remove those without a legitimate business need.
Patch Information
Google published the fix in the Android Security Bulletin September 2024. Device vendors integrate the fix through their monthly OTA updates. Users should verify the device security patch level under Settings after applying updates.
Workarounds
- No official workaround exists; patching is the only supported remediation.
- Reduce exposure by enforcing Google Play Protect and blocking sideloaded APKs via EMM.
- Retire or isolate devices that no longer receive security updates from their manufacturer.
# Verify the Android security patch level on a connected device
adb shell getprop ro.build.version.security_patch
# Expected output for remediated devices: 2024-09-01 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
