CVE-2024-0033 Overview
CVE-2024-0033 is a heap buffer overflow vulnerability in Android's ashmem-dev.cpp implementation. The flaw stems from a missing seal on shared memory regions across multiple functions in the anonymous shared memory (ashmem) subsystem. A local attacker with low privileges can trigger the overflow to escalate privileges on the affected device. Exploitation requires no user interaction and no additional execution privileges. The vulnerability affects Android versions 11 through 14 and was addressed in the February 2024 Android Security Bulletin.
Critical Impact
Local privilege escalation on Android devices without user interaction, enabling attackers to gain elevated system privileges from an unprivileged app context.
Affected Products
- Google Android 11.0
- Google Android 12.0 and 12.1
- Google Android 13.0 and 14.0
Discovery Timeline
- 2024-02-01 - Google publishes fix in the Android Security Bulletin
- 2024-02-16 - CVE-2024-0033 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-0033
Vulnerability Analysis
The vulnerability resides in ashmem-dev.cpp, a component of the Android anonymous shared memory (ashmem) subsystem used to allocate and share memory regions between processes. Multiple functions in this file fail to apply a required seal to shared memory buffers before use. Without the seal, memory protections that would normally prevent unauthorized modification of the buffer size or contents are absent. This allows a local attacker to trigger a heap buffer overflow condition [CWE-122] and write outside allocated bounds [CWE-787].
Because ashmem is used broadly across Android for inter-process communication (IPC), a corrupted region can influence memory managed by more privileged system processes. Successful exploitation results in local privilege escalation without additional execution rights and without user interaction.
Root Cause
The root cause is a missing seal operation on ashmem file descriptors within multiple code paths in ashmem-dev.cpp. Seals in Linux memfd/ashmem semantics restrict operations such as resizing or writing after a region is shared. When the seal is not applied, an attacker holding a reference to the shared region can modify it in ways the receiving process does not expect, leading to a heap buffer overflow in the consumer.
Attack Vector
An attacker requires local access via a low-privilege application installed on the device. The malicious app requests or obtains a shared ashmem region and manipulates it after sharing to overflow a heap buffer in a higher-privileged process that consumes the region. No user interaction is required, and the scope remains unchanged, but confidentiality, integrity, and availability of the target process are all impacted.
No public proof-of-concept exploit is available at this time. See the Android Native Framework Commit and Android System Core Commit for the code-level fix.
Detection Methods for CVE-2024-0033
Indicators of Compromise
- Unexpected crashes or SIGSEGV signals in system_server, mediaserver, or other privileged Android processes referencing ashmem regions.
- Installed applications that request unusual ashmem allocations or perform repeated ioctl calls against /dev/ashmem.
- Devices running Android 11 through 14 without the February 2024 security patch level applied.
Detection Strategies
- Inventory Android endpoints and compare their reported security patch level against the February 2024 bulletin baseline.
- Monitor mobile threat telemetry for privilege escalation attempts, abnormal process parentage, or unexpected setuid/setgid transitions.
- Analyze installed application binaries for suspicious use of ashmem APIs combined with attempts to resize or modify shared regions after sharing.
Monitoring Recommendations
- Enroll Android devices in a Mobile Device Management (MDM) or Enterprise Mobility Management (EMM) platform to enforce patch compliance reporting.
- Alert on devices whose ro.build.version.security_patch value predates 2024-02-01.
- Correlate mobile crash telemetry with app installation events to surface exploitation attempts against privileged services.
How to Mitigate CVE-2024-0033
Immediate Actions Required
- Apply the February 2024 Android security patch (patch level 2024-02-01 or later) to all affected devices.
- Identify devices on Android 11 through 14 that have not received the update and prioritize them for remediation.
- Restrict installation of untrusted or sideloaded applications, as local access is required for exploitation.
Patch Information
Google addressed CVE-2024-0033 in the Android Security Bulletin February 2024. The fix is implemented in the Android Native Framework Commit and the Android System Core Commit, which add the missing seal on ashmem regions. OEM devices must ingest and ship the patch through their vendor update channels, so verify the effective patch level on each device rather than the Android major version.
Workarounds
- No official workaround exists; upgrade to a build with security patch level 2024-02-01 or later.
- Limit application installs to vetted sources such as Google Play with Play Protect enabled to reduce local attack surface.
- Enforce enterprise policies that block sideloading and require minimum patch levels before granting access to corporate resources.
# Verify the security patch level on an Android device via adb
adb shell getprop ro.build.version.security_patch
# Expected output should be 2024-02-01 or later to be protected against CVE-2024-0033
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
