CVE-2018-5871 in Snapdragon Automobile
Summary
by MITRE
In Snapdragon (Automobile, Mobile, Wear) in version MDM9206, MDM9607, MDM9640, MDM9650, MSM8996AU, QCA6574AU, SD 210/SD 212/SD 205, SD 425, SD 427, SD 430, SD 435, SD 450, SD 615/16/SD 415, SD 625, SD 650/52, SD 820A, SD 835, SD 845, SD 850, SDA660, SDM429, SDM439, SDM630, SDM632, SDM636, SDM660, SDM710, Snapdragon_High_Med_2016, MAC address randomization performed during probe requests (for privacy reasons) is not done properly due to a flawed RNG which produces repeating output much earlier than expected.
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Analysis
by VulDB Data Team • 05/03/2020
This vulnerability affects Qualcomm Snapdragon automotive, mobile, and wearable platforms where the random number generator used for mac address randomization during probe requests fails to produce sufficiently random output. The flaw occurs in multiple chipsets including MDM9206, MDM9607, MDM9640, MDM9650, MSM8996AU, QCA6574AU, and various SD series processors. The improper implementation of the random number generator causes the system to generate repeating patterns in mac addresses used during wireless probe requests, which undermines privacy protections designed to prevent tracking of devices. This vulnerability specifically impacts the IEEE 802.11 wireless networking protocols where devices use randomized mac addresses to avoid being tracked across different networks and locations.
The technical implementation flaw stems from a weak random number generator that produces predictable sequences much earlier than expected in the cryptographic sense. During probe request operations, devices are supposed to randomize their mac addresses to prevent correlation attacks that could track user movements or identify specific devices across different access points. However, due to the flawed random number generation, the same mac address patterns reappear more frequently than would be expected from a properly functioning cryptographically secure random number generator. This weakness directly violates the principles of privacy protection in wireless networking and creates predictable identifiers that can be exploited by malicious actors.
The operational impact of this vulnerability extends beyond simple privacy concerns to potentially enable sophisticated tracking attacks against users of affected devices. Attackers could correlate probe requests from the same device across different networks and locations, creating detailed movement profiles and behavioral patterns. This vulnerability affects automotive systems where vehicles might be tracked through their wireless communications, mobile devices where user locations could be monitored, and wearable devices where personal activities might be inferred. The flaw essentially provides attackers with a method to de-anonymize wireless devices that should be protected by proper mac address randomization techniques, potentially compromising user privacy and location tracking security.
Mitigation strategies should focus on implementing proper random number generation techniques that meet cryptographic standards and ensuring that all wireless networking components use cryptographically secure random number generators. Organizations should consider firmware updates from device manufacturers when available, implement network monitoring to detect unusual probe request patterns, and deploy additional privacy protection measures such as network access control lists that can limit the exposure of randomized mac addresses. This vulnerability aligns with CWE-330 Use of Insufficiently Random Values and relates to ATT&CK technique T1566.002 Phishing: Spearphishing Attachment, as it could enable more sophisticated targeting based on tracking capabilities. The flaw represents a fundamental weakness in the cryptographic implementation that undermines basic privacy protections in wireless communications.