CVE-2024-23716 Overview
CVE-2024-23716 is a use-after-free vulnerability in the DevmemIntPFNotify function of devicemem_server.c in Android. The flaw stems from a race condition in kernel-level device memory management. Successful exploitation grants local privilege escalation to the kernel context without requiring additional execution privileges or user interaction. Google addressed the issue in the Android Security Bulletin for September 2024. The vulnerability is tracked under CWE-416 and affects Google Android devices using the vulnerable PowerVR GPU driver component.
Critical Impact
A local attacker holding low privileges can win a race condition in DevmemIntPFNotify to trigger a kernel use-after-free, resulting in privilege escalation to kernel context.
Affected Products
- Google Android (see Android Security Bulletin September 2024)
- Devices shipping the vulnerable devicemem_server.c kernel module
- Android builds prior to the September 2024 security patch level
Discovery Timeline
- 2024-09-11 - CVE-2024-23716 published to NVD
- 2024-09-01 - Google publishes fix in Android Security Bulletin
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-23716
Vulnerability Analysis
The vulnerability resides in DevmemIntPFNotify, a routine in devicemem_server.c that handles page fault notifications for device memory allocations. Concurrent execution paths access a shared kernel object without adequate synchronization. One thread can free the object while another still holds a reference, producing a classic use-after-free condition ([CWE-416]).
Once the object memory is reclaimed and repopulated by attacker-controlled data, the stale reference can be dereferenced by the kernel. This corrupts kernel state and allows the attacker to redirect execution or manipulate privileged structures. The result is local escalation of privilege into the kernel with no user interaction required.
Root Cause
The root cause is missing or insufficient locking around a lifecycle-managed object in DevmemIntPFNotify. Reference counting or synchronization primitives fail to serialize free and notify operations. A race window exists between the free path and the notification path, allowing a freed pointer to remain reachable.
Attack Vector
Exploitation requires local code execution on the device, typically via a malicious or compromised application with standard user privileges. The attacker triggers concurrent operations against the device memory subsystem to win the race. Attack complexity is high because the race window is narrow and timing-sensitive, but no user interaction is required. Successful exploitation yields kernel privileges, undermining Android's application sandbox and SELinux boundaries.
No public proof-of-concept exploit is currently listed for CVE-2024-23716, and the CVE is not present on the CISA Known Exploited Vulnerabilities catalog. Refer to the Android Security Bulletin September 2024 for vendor-published technical context.
Detection Methods for CVE-2024-23716
Indicators of Compromise
- Unexpected kernel oops, panics, or crashes referencing DevmemIntPFNotify or the PowerVR/pvrsrvkm driver in dmesg or logcat.
- Applications with no legitimate need repeatedly invoking device memory or GPU ioctls at high frequency.
- Post-exploit artifacts such as SELinux enforcement failures or processes running with unexpected UID 0 privileges.
Detection Strategies
- Monitor Android security patch levels across the mobile fleet and flag devices reporting a patch level earlier than 2024-09-01.
- Inspect kernel logs on rooted or managed devices for repeated faults associated with the device memory subsystem.
- Correlate mobile threat defense telemetry with application behavior that exercises GPU or DRM ioctls in unusual patterns.
Monitoring Recommendations
- Enforce mobile device management (MDM) compliance checks that require the September 2024 or later Android security patch level.
- Alert on newly installed applications that request or interact with low-level graphics or memory driver interfaces without a business justification.
- Track crash telemetry from Android devices to identify recurring faults consistent with race-condition exploitation attempts.
How to Mitigate CVE-2024-23716
Immediate Actions Required
- Apply the September 2024 Android security patch level or later on all managed devices, per the Android Security Bulletin September 2024.
- Identify device models that have reached end-of-support and replace them or isolate them from sensitive data.
- Restrict sideloading and enforce installation only from vetted application sources via MDM policy.
Patch Information
Google released the fix in the September 2024 Android Security Bulletin. Device manufacturers ship the corresponding patch level (2024-09-01 or later) through their own update channels. Administrators should confirm both the OS patch level and any OEM-specific vendor image updates covering the PowerVR/pvrsrvkm driver.
Workarounds
- No official workaround exists; patching is the only supported remediation.
- Reduce exposure by limiting untrusted applications and enforcing Play Protect and MDM application allowlisting.
- Segment high-risk users onto devices that receive timely security updates from the OEM.
# Verify Android security patch level on a device via ADB
adb shell getprop ro.build.version.security_patch
# Expected output for remediation: 2024-09-01 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
