CVE-2025-21437 Overview
CVE-2025-21437 is a memory corruption vulnerability affecting a broad set of Qualcomm chipsets and firmware. The flaw occurs when memory map or unmap IOCTL (Input/Output Control) operations are processed simultaneously, leading to a use-after-free condition classified as [CWE-416]. A local attacker with low privileges can trigger the race condition to corrupt kernel memory and compromise confidentiality, integrity, and availability of the affected device. Qualcomm disclosed the issue in its April 2025 Security Bulletin. The vulnerability affects automotive, connectivity, and compute platforms including SA8155P, SA8295P, SA8775P, and multiple QCA6xxx Wi-Fi/Bluetooth SoCs.
Critical Impact
Local attackers can trigger a use-after-free race condition in Qualcomm IOCTL handlers to corrupt kernel memory, potentially leading to privilege escalation or arbitrary code execution in kernel context.
Affected Products
- Qualcomm automotive platforms including SA6155P, SA8155P, SA8195P, SA8255P, SA8295P, SA8620P, SA8650P, SA8770P, SA8775P, and SA9000P
- Qualcomm connectivity SoCs including QCA6574, QCA6574A, QCA6574AU, QCA6595, QCA6595AU, QCA6688AQ, QCA6696, QCA6698AQ, and QCA6797AQ
- Qualcomm QAM series (QAM8255P, QAM8295P, QAM8620P, QAM8650P, QAM8775P), QAMSRV1H/M, and SRV1H/L/M firmware
Discovery Timeline
- 2025-04-07 - CVE-2025-21437 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-21437
Vulnerability Analysis
The vulnerability resides in Qualcomm firmware code that handles memory map and unmap IOCTL operations. When two IOCTL requests execute concurrently against the same memory object, the driver fails to serialize access. One thread can free a memory structure while another thread still holds a reference to it. Subsequent dereference of the stale pointer results in use-after-free memory corruption in kernel context. Successful exploitation impacts device stability and can be leveraged to escalate privileges from an unprivileged local process.
Root Cause
The root cause is missing or insufficient synchronization between concurrent IOCTL handlers that manage the lifecycle of shared memory objects. The driver does not enforce mutual exclusion around allocation, mapping, and freeing operations. This creates a time-of-check to time-of-use window in which one thread frees an object while another operates on it, matching the pattern described by [CWE-416] Use After Free.
Attack Vector
Exploitation requires local access to the device with the ability to open the affected driver's IOCTL interface. An attacker with low privileges issues concurrent map and unmap IOCTL calls from multiple threads to race the handler. Winning the race corrupts kernel memory structures. No user interaction is required. The vulnerability cannot be triggered remotely over a network, limiting exposure to local attackers, malicious applications, or compromised processes on the device.
No public proof-of-concept exploit is available at the time of publication. See the Qualcomm April 2025 Security Bulletin for technical details.
Detection Methods for CVE-2025-21437
Indicators of Compromise
- Unexpected kernel panics, watchdog resets, or crashes referencing memory mapping subsystems on affected Qualcomm platforms
- Kernel logs showing corrupted pointers, invalid free operations, or SLUB/SLAB allocator errors originating from IOCTL handlers
- Unprivileged processes issuing high-frequency, concurrent map/unmap IOCTL calls against Qualcomm driver device nodes
Detection Strategies
- Baseline legitimate IOCTL usage patterns for Qualcomm driver interfaces and alert on anomalous multi-threaded bursts from a single process
- Ingest kernel crash telemetry into a centralized data lake and correlate crash signatures with process ancestry and recently installed applications
- Monitor for privilege escalation chains that begin with local unprivileged processes accessing hardware driver device files
Monitoring Recommendations
- Collect kernel dmesg output, logcat on Android-based platforms, and vendor crash dumps for retrospective analysis
- Track firmware versions across the automotive and IoT fleet and flag devices missing the April 2025 Qualcomm patch
- Alert on new binaries invoking ioctl() against Qualcomm memory subsystem device nodes from non-system UIDs
How to Mitigate CVE-2025-21437
Immediate Actions Required
- Apply the firmware update from OEMs that incorporates the Qualcomm April 2025 Security Bulletin fixes for CVE-2025-21437
- Inventory all deployed Qualcomm-based automotive, IoT, and connectivity devices and prioritize patch rollout for those exposing untrusted application execution
- Restrict installation of untrusted applications on affected devices until firmware updates are validated and deployed
Patch Information
Qualcomm released fixes as part of its April 2025 Security Bulletin. Device OEMs must integrate the patched firmware into their downstream builds and distribute updates through their standard channels. Review the Qualcomm April 2025 Security Bulletin for the authoritative list of affected chipsets and remediation guidance.
Workarounds
- Enforce least privilege on affected devices and disallow untrusted local code execution where feasible
- Restrict access to Qualcomm driver device nodes to system components only through SELinux or equivalent mandatory access control policies
- Increase monitoring of kernel crash telemetry until vendor firmware patches are applied across the fleet
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
