CVE-2018-11893 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 vendor scan request, when input argument - length of request IEs is greater than maximum can lead to a buffer overflow.
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Analysis
by VulDB Data Team • 05/17/2023
This vulnerability exists within the linux kernel implementation across multiple android variants including Android for MSM, Firefox OS for MSM, and QRD Android platforms developed by Code Aurora Forum. The flaw manifests during the processing of vendor scan requests where the system fails to properly validate input parameters, specifically the length of request information elements. When an attacker provides an input argument exceeding the maximum allowable length, the kernel fails to enforce proper bounds checking, creating a condition that allows for buffer overflow exploitation.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the wireless networking subsystem of the android kernel. The vendor scan request processing code does not perform proper boundary checks on the length parameter before attempting to copy or process the information elements. This allows an attacker to craft malicious input that exceeds the allocated buffer space, leading to memory corruption that can be exploited to execute arbitrary code or cause system instability. The vulnerability specifically affects the wireless driver components that handle vendor-specific scan operations, making it particularly dangerous in environments where wireless connectivity is actively used.
The operational impact of this vulnerability extends beyond simple system crashes or hangs, as it presents a potential path for privilege escalation and remote code execution. An attacker positioned within the wireless network's reach could exploit this flaw to gain elevated privileges on the target device, potentially leading to complete system compromise. The vulnerability affects all versions of android released by CAF, making it widespread across numerous devices and deployments. The buffer overflow condition creates memory corruption that can be leveraged to overwrite critical system data structures, potentially allowing attackers to redirect execution flow or inject malicious code into the kernel space.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and bounds checking within the wireless subsystem. The recommended approach involves adding explicit length validation before processing vendor scan requests, ensuring that all input parameters are verified against maximum allowable values. System administrators should prioritize applying vendor patches and updates that address this specific buffer overflow condition. Additionally, implementing kernel hardening techniques such as stack canaries, address space layout randomization, and kernel address space protection can provide additional layers of defense. Organizations should also consider network segmentation and monitoring to detect anomalous wireless scan activities that might indicate exploitation attempts. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of inadequate input validation leading to memory corruption. The attack surface is consistent with ATT&CK technique T1059, where adversaries leverage system vulnerabilities to execute malicious code, particularly in the context of wireless network exploitation.