CVE-2019-2235 in Snapdragon Auto
Summary
by MITRE
Buffer overflow occurs when emulated RPMB is used due to sector size assumptions in the TA rollback protection logic. in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer Electronics Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wired Infrastructure and Networking in MDM9206, MDM9607, MDM9650, MDM9655, MSM8996AU, QCS404, QCS605, Qualcomm 215, SD 410/12, SD 425, SD 427, SD 430, SD 435, SD 439 / SD 429, SD 450, SD 625, SD 632, SD 636, SD 712 / SD 710 / SD 670, SD 820, SD 820A, SD 835, SD 845 / SD 850, SD 8CX, SDA660, SDM439, SDM630, SDM660, Snapdragon_High_Med_2016, SXR1130
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Analysis
by VulDB Data Team • 07/12/2020
The vulnerability described in CVE-2019-2235 represents a critical buffer overflow condition within the Trusted Application (TA) rollback protection mechanism of Qualcomm's Snapdragon chipsets. This flaw specifically manifests when emulated RPMB (Replay Protection Memory Block) functionality is utilized, creating a scenario where the system's assumption about sector sizes leads to improper memory handling during rollback protection operations. The vulnerability affects a comprehensive range of Qualcomm's automotive, mobile, and IoT products, spanning from entry-level processors like the SD 410/12 to high-end flagship chips such as the SD 845/SD 850, indicating the widespread nature of this security weakness.
The technical root cause of this vulnerability lies in the improper handling of memory boundaries within the TA rollback protection logic. When the system attempts to process RPMB operations, it makes assumptions about the sector size that may not align with actual memory allocation patterns. This mismatch creates opportunities for attackers to overflow buffers and potentially overwrite adjacent memory regions, leading to arbitrary code execution or system instability. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, where insufficient bounds checking allows data to be written beyond allocated buffer boundaries, and it aligns with ATT&CK technique T1059.007 for execution through command and scripting interpreter. The flaw is particularly dangerous because it operates at the Trusted Application level, which means it could potentially be exploited to bypass security mechanisms that are supposed to protect against malicious firmware updates or unauthorized modifications.
The operational impact of this vulnerability extends across multiple domains of Qualcomm's product portfolio, affecting automotive systems, mobile devices, and IoT infrastructure. Attackers who successfully exploit this vulnerability could potentially manipulate rollback protection mechanisms designed to prevent downgrade attacks or unauthorized firmware modifications, thereby undermining the security chain that protects these devices from malicious updates. The affected chipsets include the MDM9206, MDM9607, MDM9650, MDM9655, MSM8996AU, and numerous other processors across different product lines, indicating that the vulnerability could compromise a significant portion of connected devices in the field. This weakness particularly impacts systems where secure boot and rollback protection are critical, such as automotive infotainment systems, industrial IoT deployments, and mobile devices where firmware integrity is paramount.
Mitigation strategies for this vulnerability should focus on firmware updates provided by Qualcomm, which would address the buffer overflow conditions in the TA rollback protection logic. Organizations should prioritize applying patches to all affected devices, particularly those in critical infrastructure or automotive applications where security is paramount. Additional protective measures include implementing runtime monitoring for anomalous memory access patterns, utilizing secure boot mechanisms that validate all firmware components, and maintaining strict control over firmware update processes to prevent unauthorized modifications. The vulnerability highlights the importance of proper memory management in secure environments and demonstrates how assumptions about hardware characteristics can lead to security flaws. Security teams should also consider implementing network segmentation and access controls to limit potential attack surfaces, while monitoring for indicators of compromise that might suggest exploitation attempts targeting this specific vulnerability.