CVE-2025-1533 Overview
CVE-2025-1533 is a stack buffer overflow vulnerability [CWE-121] in the AsIO3.sys kernel driver distributed with the ASUS Armoury Crate application. An attacker with local, low-privileged access can manipulate input passed to the driver to overflow a stack buffer. Successful exploitation triggers a system crash (Bug Check / BSOD) and may lead to undefined kernel execution behavior. The flaw was reported through Cisco Talos as TALOS-2025-2144 and disclosed by ASUS in the Armoury Crate App section of the ASUS Security Advisory.
Critical Impact
Local low-privileged attackers can crash affected Windows systems through the AsIO3.sys driver and potentially achieve undefined kernel-mode execution.
Affected Products
- ASUS Armoury Crate App
- AsIO3.sys kernel driver bundled with Armoury Crate
- Windows systems where the vulnerable driver is loaded
Discovery Timeline
- 2025-05-12 - CVE-2025-1533 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-1533
Vulnerability Analysis
The vulnerability is a classic stack-based buffer overflow inside the AsIO3.sys Windows kernel driver. The driver exposes an I/O interface reachable from user mode through IOCTL requests. When the driver processes attacker-controlled input, it writes data into a fixed-size stack buffer without validating the input length against the destination bounds.
Because the overflow occurs in kernel context, corrupting the kernel stack destabilizes control flow. The immediate observable effect is a system crash (BSOD). Depending on the corrupted data and return addresses, an attacker may influence kernel execution beyond a simple denial of service.
The vulnerability requires local access and low privileges (AV:L, PR:L), and no user interaction is required. Availability impact on the affected system is high, since a successful trigger reliably halts the operating system.
Root Cause
The root cause is missing bounds validation on user-supplied input before it is copied into a stack buffer inside the driver's IOCTL handler. The driver trusts the size or structure of the incoming request instead of enforcing an explicit length check against the destination buffer.
Attack Vector
A local user opens a handle to the AsIO3.sys device object and issues a crafted DeviceIoControl request containing an oversized or malformed payload. The driver copies the payload into a stack buffer, overwriting adjacent stack memory including saved return addresses and local variables. This yields a bug check at minimum, with potential for kernel-mode code redirection in more advanced exploitation scenarios. See the Talos Vulnerability Report TALOS-2025-2144 for technical detail.
No verified public proof-of-concept code is included in this disclosure. The vulnerability mechanism is described in prose only.
Detection Methods for CVE-2025-1533
Indicators of Compromise
- Unexpected Windows bug checks (BSOD) referencing AsIO3.sys in the crash dump stack trace
- Repeated crashes on endpoints running ASUS Armoury Crate shortly after non-administrative user activity
- Presence of vulnerable versions of AsIO3.sys loaded in \Device\ namespace on managed endpoints
Detection Strategies
- Inventory endpoints for the presence and version of AsIO3.sys and the Armoury Crate application
- Monitor for user-mode processes opening handles to the AsIO3 device object followed by DeviceIoControl calls with abnormally sized input buffers
- Correlate Windows Error Reporting (WER) crash telemetry with driver names to surface AsIO3.sys faults across the fleet
Monitoring Recommendations
- Ingest Windows kernel crash events and driver-load events (Sysmon Event ID 6) into a SIEM for correlation
- Alert on new or unsigned versions of AsIO3.sys being loaded outside of vendor update windows
- Track process lineage of any binary interacting with the AsIO3 device from non-administrative sessions
How to Mitigate CVE-2025-1533
Immediate Actions Required
- Update ASUS Armoury Crate to the fixed version referenced in the ASUS Security Advisory
- Identify all endpoints with AsIO3.sys loaded and prioritize patching of shared or multi-user workstations
- Restrict local access on affected systems until the driver is updated
Patch Information
ASUS has published a fix under the "Security Update for Armoury Crate App" section of the ASUS Security Advisory. Apply the updated Armoury Crate release, which replaces the vulnerable AsIO3.sys driver with a version that validates input length before copying data into the stack buffer.
Workarounds
- Uninstall Armoury Crate on systems that do not require ASUS peripheral or motherboard management features
- Block loading of the vulnerable AsIO3.sys version using Windows Defender Application Control (WDAC) or a driver blocklist policy
- Limit local logon rights on affected hosts to reduce the population of users able to reach the driver
# Example: query loaded driver version on Windows via PowerShell
Get-CimInstance Win32_SystemDriver | Where-Object { $_.Name -eq 'AsIO3' } | Select-Object Name, PathName, State, Started
# Example: remove the Armoury Crate package (run elevated)
winget uninstall --name "Armoury Crate"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
