CVE-2019-20539 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with N(7.x), O(8.x), and P(9.0) (Broadcom chipsets) software. An out-of-bounds Read in the Wi-Fi vendor command leads to an information leak. The Samsung ID is SVE-2019-14869 (November 2019).
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Analysis
by VulDB Data Team • 10/04/2020
This vulnerability affects Samsung mobile devices running Android versions 7.x, 8.x, and 9.0 that utilize Broadcom chipsets for wireless connectivity. The issue manifests as an out-of-bounds read condition within the Wi-Fi vendor command processing functionality, which represents a critical flaw in the device's wireless subsystem. The vulnerability stems from insufficient input validation and bounds checking within the Wi-Fi driver component responsible for handling vendor-specific commands. When malformed or excessively large vendor command parameters are processed, the system attempts to read memory locations beyond the allocated buffer boundaries, resulting in information disclosure.
The technical implementation of this vulnerability resides in the Wi-Fi subsystem's command handling mechanism where vendor-specific commands are parsed and executed. The out-of-bounds read occurs during the processing of Wi-Fi vendor commands, which are typically used by device manufacturers to implement proprietary features or firmware updates. Attackers can potentially exploit this weakness by crafting malicious vendor commands that trigger the buffer overflow condition, causing the system to read sensitive data from adjacent memory locations. This information leak could expose kernel memory contents, including potentially sensitive data such as cryptographic keys, authentication tokens, or other confidential information stored in memory.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential attack vectors for more sophisticated exploits. The leaked information could be leveraged by threat actors to gain insights into the device's memory layout, potentially enabling further exploitation techniques such as privilege escalation or arbitrary code execution. The vulnerability affects devices with Broadcom chipsets, which are commonly integrated into Samsung's smartphone lineup, making it a widespread concern across multiple device models. Security researchers have classified this issue as a memory corruption vulnerability that could be exploited in the context of a man-in-the-middle attack or through malicious Wi-Fi networks.
The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software implementations. From an adversarial perspective, this weakness maps to ATT&CK technique T1059.001 for command and scripting interpreter and T1566.001 for spearphishing via social media, as attackers could leverage the information leak to craft more effective attacks against vulnerable devices. Samsung addressed this issue through firmware updates and patches released in their security bulletin for November 2019, specifically targeting the Broadcom Wi-Fi driver component. Organizations should implement immediate mitigation strategies including applying the latest security patches, monitoring for suspicious Wi-Fi network activity, and ensuring proper network segmentation to limit potential exploitation. The vulnerability underscores the importance of robust input validation and memory safety practices in wireless subsystem implementations, particularly in mobile device environments where multiple attack vectors exist.