CVE-2018-11298 in Android
Summary
by MITRE
In all android releases(Android for MSM, Firefox OS for MSM, QRD Android) from CAF using the linux kernel, while processing SET_PASSPOINT_LIST vendor command HDD does not make sure that the realm string that gets passed by upper-layer is NULL terminated. This may lead to buffer overflow as strlen is used to get realm string length to construct the PASSPOINT WMA command.
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Analysis
by VulDB Data Team • 05/16/2023
This vulnerability exists in Android-based systems utilizing Qualcomm's Linux kernel implementations including MSM variants, Firefox OS for MSM, and QRD Android platforms. The issue manifests within the Host Device Driver (HDD) component when processing the SET_PASSPOINT_LIST vendor command, which is part of the Wi-Fi Passpoint functionality enabling automatic network connection based on credentials stored in the device. The flaw occurs during the handling of realm strings passed from upper-layer components to the driver, where the HDD fails to validate or ensure proper null termination of these strings before processing.
The technical implementation defect stems from the HDD's reliance on the standard strlen() function to determine the length of realm strings when constructing PASSPOINT WMA commands. This approach assumes that all input strings are properly null-terminated, but when upper-layer components fail to provide null-terminated strings, the strlen() function continues reading memory beyond the intended string boundaries until it encounters a null byte. This behavior creates a classic buffer overflow condition where the driver attempts to copy more data than allocated buffer space can accommodate, potentially overwriting adjacent memory regions and corrupting critical system data structures.
The operational impact of this vulnerability extends beyond simple memory corruption, as it represents a potential vector for privilege escalation and system compromise. Attackers could potentially exploit this flaw by crafting malicious Passpoint configuration data that includes non-null-terminated realm strings, leading to unpredictable behavior including system crashes, denial of service conditions, or more severe exploitation scenarios. The vulnerability affects multiple Qualcomm-based Android platforms, making it particularly concerning for widespread deployment across various mobile devices and IoT implementations that rely on these kernel components for Wi-Fi connectivity management.
From a cybersecurity perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, covering heap-based buffer overflow scenarios, while also mapping to ATT&CK technique T1068, which involves exploiting legitimate credentials or system processes to gain elevated privileges. The flaw demonstrates a classic input validation weakness where the system fails to properly sanitize or verify data integrity before processing, creating an opportunity for attackers to manipulate memory layout and potentially execute arbitrary code within the kernel context. Mitigation strategies should focus on implementing proper string validation checks within the HDD component, ensuring all realm strings are explicitly null-terminated before strlen() operations, and potentially adding bounds checking mechanisms to prevent overflow conditions during WMA command construction. Additionally, system updates should enforce proper input sanitization at all layers of the network stack to prevent similar vulnerabilities from being exploited in other components of the Passpoint functionality.