CVE-2015-2291

What Is the Intel Ethernet Diagnostics Driver?

The Intel Network Adapter Diagnostic Driver (IQVW32.sys for 32-bit and IQVW64.sys for 64-bit) is a legitimate kernel-mode Windows driver distributed by Intel for diagnostics and testing of Intel Ethernet network adapters. As a Microsoft-signed driver, it can be loaded on Windows systems without triggering driver signing policy blocks.

Kernel-mode drivers run with the highest privilege level in Windows — kernel/SYSTEM. A vulnerability in a kernel driver that allows user-mode processes to interact with kernel memory in unintended ways is particularly dangerous because it can be exploited to read/write arbitrary kernel memory, corrupt security-sensitive structures, or terminate security processes.

CVE-2015-2291 is notable not just as a local privilege escalation, but as a Bring Your Own Vulnerable Driver (BYOVD) target — attackers deliberately load this legitimate, signed, vulnerable Intel driver onto victim systems to exploit its kernel access, bypassing Windows driver signing requirements entirely.

Overview

CVE-2015-2291 is an improper input validation vulnerability in Intel's IQVW32.sys and IQVW64.sys Ethernet diagnostics drivers that allows a local attacker to cause arbitrary kernel memory corruption — enabling privilege escalation, system crash (DoS), or kernel code execution. The primary real-world exploitation pattern is BYOVD (Bring Your Own Vulnerable Driver): ransomware operators and APT groups drop the vulnerable Intel driver onto victim systems, exploit CVE-2015-2291 to gain kernel-level access, and use that access to terminate EDR/AV security processes that would otherwise detect and block their payloads. ransomwareUse: true reflects confirmed use in ransomware campaigns.

Affected Versions

Intel released updated drivers addressing CVE-2015-2291 via INTEL-SA-00051.

Technical Details

Root Cause: Improper Input Validation in Kernel IOCTL Handling

The Intel Ethernet diagnostics driver exposes device control (IOCTL) interfaces that allow user-mode processes to interact with the driver. The driver fails to properly validate inputs received via these IOCTL calls — specifically, failing to bounds-check user-supplied buffer lengths or pointer values before using them in kernel-mode operations.

An attacker who can load the driver (or who finds it already installed) can send crafted IOCTL requests that:

• Write arbitrary data to kernel memory — by supplying a kernel address as a target in a poorly validated IOCTL operation
• Corrupt security-critical kernel structures — including the EPROCESS structure (which controls process privileges), token structures, or security callback registrations
• Terminate protected processes — by directly manipulating kernel structures that determine which processes are protected by security software

BYOVD Attack Pattern

The BYOVD technique exploits the trust Windows places in Microsoft-signed drivers:

1. Attacker gains initial foothold (phishing, initial exploit) with user-level access
2. Drop the vulnerable Intel driver (IQVW64.sys) to disk — as a signed driver, it can be loaded via NtLoadDriver or Service Control Manager without triggering Secure Boot or Driver Signing enforcement
3. Load the driver — even without admin rights in some configurations, or after UAC bypass
4. Exploit CVE-2015-2291 via crafted IOCTL to write to kernel memory
5. Disable security software — corrupt kernel callbacks registered by EDR/AV, or directly terminate security processes from kernel context
6. Deploy ransomware or APT implant — now undetected by the security tools that were just killed

Attack Characteristics

Discovery

The vulnerability was identified in Intel's driver and formally disclosed in August 2017 via INTEL-SA-00051. The driver was added to ESET's blocklist and other security tools' BYOVD blocklists. However, the signed driver's availability in the wild (on systems where Intel NICs were installed) meant it remained exploitable in BYOVD campaigns long after disclosure.

Exploitation Context

• Ransomware BYOVD campaigns: Multiple ransomware operators including those deploying BlackByte, AvosLocker, and RobbinHood ransomware used BYOVD techniques — RobbinHood specifically referenced CVE-2015-2291 in analysis by Sophos; similar patterns were documented in other campaigns
• APT BYOVD: NOBELIUM/APT29 and other nation-state actors have been documented using BYOVD techniques to disable security tools; CVE-2015-2291 has been catalogued as a BYOVD target by security researchers
• LOLDrivers: The vulnerability is tracked in the LOLDrivers (Living Off The Land Drivers) project as a known malicious use driver — IQVW64.sys appears in threat hunting rules and detection signatures for BYOVD activity
• CISA KEV (2023): Added February 2023, reflecting confirmed active exploitation 6+ years after Intel's security advisory

Remediation

1. Update Intel Ethernet drivers — install the updated drivers from Intel INTEL-SA-00051 that fix CVE-2015-2291. Update via Intel Driver & Support Assistant or directly from Intel's support site.

2. Block vulnerable driver hashes — add known-vulnerable IQVW32.sys and IQVW64.sys file hashes to your endpoint protection blocklist and Windows Defender Application Control (WDAC) policies. Microsoft's Vulnerable Driver Blocklist (HVCI mode) includes this driver.

3. Enable Hypervisor-Protected Code Integrity (HVCI) — HVCI (also called Memory Integrity in Windows Security) prevents loading of unsigned drivers and known-vulnerable signed drivers. Enable via Windows Security → Device Security → Core Isolation.

4. Monitor for driver loading events — alert on loading of IQVW32.sys or IQVW64.sys via Sysmon Event ID 6 (driver loaded) if not expected on the system. This is a key BYOVD detection signal.

5. Apply WDAC / Application Control policies — enforce Windows Defender Application Control with the vulnerable driver blocklist to prevent loading of known BYOVD-used drivers.

6. Threat hunt for indicators — search EDR telemetry for file writes of IQVW32.sys or IQVW64.sys to system directories followed by service creation events, which is the standard BYOVD deployment pattern.