CVE-2013-2597

What is the Code Aurora ACDB Audio Driver?

The Audio Calibration Database (ACDB) driver is a kernel-mode component developed by the Code Aurora Forum — Qualcomm's open-source initiative for mobile platform software. The ACDB driver manages audio hardware calibration parameters for Qualcomm Snapdragon system-on-chip (SoC) processors. It is deployed in a large fraction of Android devices using Qualcomm chipsets, running as a kernel driver that exposes an IOCTL interface to userspace applications needing to read or write audio calibration data.

Overview

CVE-2013-2597 is a stack-based buffer overflow vulnerability (CWE-119) in the Code Aurora ACDB audio calibration kernel driver. A local process can invoke an IOCTL call to the ACDB driver with a crafted data structure that triggers a stack overflow in the kernel driver's input handling routine. Because the overflow occurs in kernel space, it allows an attacker-controlled process to overwrite kernel stack data, redirect kernel execution, and escalate privileges to root on affected Android devices.

Affected Versions

The vulnerability affects a broad range of Android devices using Qualcomm chipsets, as the ACDB driver is a common component across Snapdragon-based Android smartphones and tablets.

Technical Details

The ACDB driver exposes device control functionality through ioctl() calls from userspace. The vulnerable code path handles an IOCTL command where the kernel copies user-supplied data into a fixed-size stack buffer without validating the length of the input against the buffer size. An attacker calling the IOCTL with an oversized payload overflows the stack buffer, overwriting the kernel stack frame including the return address.

Kernel stack overflow exploitation:

• Overwriting the return address redirects control when the vulnerable kernel function returns
• On ARM-based Android devices (typical for Qualcomm Snapdragon), the attacker redirects execution to shellcode or a ROP chain in controlled memory
• The result is arbitrary code execution at kernel privilege (ring 0), which can directly modify the process's credential structure to grant root

Attack vector (AV:L, PR:N): Any process running on the device — including a malicious app — can open the ACDB device node and invoke the vulnerable IOCTL. No elevated permissions are required to trigger the overflow, making this accessible to untrusted Android applications that have been installed on the device.

Discovery

Discovered through security research into Qualcomm driver IOCTLs on Android. Reported to Code Aurora Foundation, which published a security advisory and patch. The CVE was assigned in 2013 but published in August 2014, reflecting the delayed disclosure common for device-specific Android kernel vulnerabilities pending OEM patch distribution.

Exploitation Context

CISA confirmed exploitation in the wild. Qualcomm driver IOCTL vulnerabilities were a significant attack surface for Android privilege escalation during 2013–2016. The attack pattern — install a malicious app, use a kernel driver IOCTL overflow to gain root — was the basis for Android rooting tools and malware including components of the Stagefright-era exploit chains. Many Android devices running Qualcomm chipsets received patches slowly or never, given the fragmented Android update ecosystem.

Remediation

1. Apply OEM security updates for affected Android devices — device manufacturers (Samsung, LG, etc.) distributed patches incorporating the Code Aurora fix
2. Android devices that no longer receive security updates from their manufacturer should be treated as end-of-life
3. For enterprise Android management: use MDM/EMM policies that enforce minimum OS security patch levels; block enrollment of devices below the required patch level
4. Restrict installation of apps to trusted sources (Google Play with Play Protect scanning)
5. Consider runtime application self-protection (RASP) or mobile threat defense (MTD) tools that detect privilege escalation attempts