CVE-2013-6392 in Android-msm
Summary
by MITRE
The genlock_dev_ioctl function in genlock.c in the Genlock driver for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, does not properly initialize a certain data structure, which allows local users to obtain sensitive information from kernel stack memory via a crafted GENLOCK_IOC_EXPORT ioctl call.
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Analysis
by VulDB Data Team • 01/11/2022
The vulnerability identified as CVE-2013-6392 resides within the Genlock driver component of the Linux kernel version 3.x series, specifically affecting Qualcomm Innovation Center's Android contributions for MSM devices and related products. This issue manifests in the genlock_dev_ioctl function located in the genlock.c source file, representing a critical security flaw that compromises the integrity of kernel memory operations. The vulnerability stems from improper initialization of a data structure during ioctl command processing, creating a pathway for unauthorized information disclosure.
The technical flaw occurs when the genlock_dev_ioctl function processes the GENLOCK_IOC_EXPORT ioctl command without adequately initializing a specific data structure before using it. This incomplete initialization leaves sensitive kernel stack memory contents accessible to local attackers who can craft malicious ioctl calls to extract this uninitialized data. The vulnerability represents a classic information disclosure weakness that falls under CWE-1284, which specifically addresses improper initialization of data structures in kernel space. The flaw essentially creates a data leak mechanism where kernel memory addresses, previously used variables, or other sensitive information remains accessible in the uninitialized memory segments.
From an operational perspective, this vulnerability presents significant risks to Android devices utilizing Qualcomm MSM chipsets, as local attackers with basic user privileges can exploit this weakness to gain access to kernel memory contents. The extracted information could potentially include memory addresses, kernel data structures, or other sensitive information that could aid in further exploitation attempts. This type of information disclosure vulnerability aligns with ATT&CK technique T1005, which covers data from local system storage, and can serve as a foundation for more sophisticated attacks including privilege escalation or kernel exploitation. The impact extends beyond simple information leakage as the leaked kernel memory contents could reveal patterns or structures that attackers might leverage to bypass security mechanisms or predict memory layouts.
Mitigation strategies for CVE-2013-6392 require immediate patching of affected kernel versions through proper initialization of the data structure within the genlock_dev_ioctl function. System administrators and device manufacturers should prioritize updating to kernel versions that address this specific initialization flaw, ensuring that all data structures are properly initialized before use. Additionally, implementing proper kernel memory protection mechanisms and maintaining up-to-date security patches for Android devices can prevent exploitation of this vulnerability. The fix should involve explicit initialization of the affected data structure with zero values or appropriate default values before processing the ioctl command, preventing the leakage of uninitialized kernel memory contents. Organizations should also consider implementing runtime monitoring to detect suspicious ioctl activity patterns that might indicate exploitation attempts against this vulnerability.