CVE-2017-15837 in Android
Summary
by MITRE
In Qualcomm Android for MSM, Firefox OS for MSM, and QRD Android with all Android releases from CAF using the Linux kernel before security patch level 2018-04-05, a policy for the packet pattern attribute NL80211_PKTPAT_OFFSET is not defined which can lead to a buffer over-read in nla_get_u32().
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Analysis
by VulDB Data Team • 01/21/2020
The vulnerability identified as CVE-2017-15837 represents a critical buffer over-read flaw affecting Qualcomm Android platforms and related operating systems. This issue manifests within the Linux kernel implementation of wireless networking components, specifically in the handling of packet pattern attributes for nl80211 subsystem operations. The flaw exists in devices utilizing Qualcomm's Mobile Services Module (MSM) architecture and QRD Android platforms, with affected systems spanning all Android releases from the Common Android Framework (CAF) that were operational prior to the security patch level of April 5, 2018. The vulnerability stems from the absence of proper policy definition for the NL80211_PKTPAT_OFFSET packet pattern attribute, creating a scenario where maliciously crafted network packets could trigger unauthorized memory access patterns.
The technical implementation of this vulnerability occurs within the nla_get_u32() function, which serves as a network link attribute getter for unsigned 32-bit values. When processing wireless packet pattern attributes without proper validation of the NL80211_PKTPAT_OFFSET parameter, the kernel fails to enforce bounds checking on buffer allocations. This allows an attacker to manipulate network configuration parameters in a way that causes the kernel to read beyond allocated memory boundaries, potentially accessing sensitive kernel memory regions. The flaw operates at the kernel level within the wireless subsystem, specifically in the nl80211 wireless configuration interface, where network attributes are parsed and processed. This represents a classic buffer over-read vulnerability that can lead to information disclosure or system instability.
The operational impact of CVE-2017-15837 extends beyond simple information disclosure, as it can enable attackers to extract kernel memory contents that may contain sensitive data such as cryptographic keys, session tokens, or other confidential information. The vulnerability affects devices running on Qualcomm MSM platforms, including smartphones, tablets, and IoT devices that utilize Qualcomm's wireless chipsets. Attackers can exploit this weakness by sending specially crafted wireless configuration commands to the affected devices, potentially leading to privilege escalation or complete system compromise. The vulnerability affects a broad range of devices due to the widespread adoption of Qualcomm's MSM architecture in Android devices, making it particularly concerning from a security perspective. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation and information disclosure techniques, potentially enabling adversaries to gain deeper system access and extract sensitive data.
Mitigation strategies for this vulnerability require immediate deployment of security patches from Qualcomm and device manufacturers, specifically targeting the Linux kernel components that handle nl80211 wireless configuration operations. System administrators should prioritize updating devices to security patch levels released on or after April 5, 2018, which contain the necessary fixes for the NL80211_PKTPAT_OFFSET attribute handling. Organizations should also implement network monitoring to detect unusual wireless configuration patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-121, which describes buffer overflow conditions in heap-based memory allocation scenarios, and represents a specific instance where improper input validation leads to memory access violations. Device manufacturers should consider implementing additional kernel hardening measures such as stack canaries and memory protection mechanisms to further reduce the attack surface and prevent exploitation of similar buffer over-read vulnerabilities in the wireless subsystem.