CVE-2017-9708 in Android
Summary
by MITRE
In Android for MSM, Firefox OS for MSM, QRD Android, with all Android releases from CAF using the Linux kernel, in the camera driver, the function "msm_ois_power_down" is called without a mutex and a race condition can occur in variable "*reg_ptr" of sub function "msm_camera_config_single_vreg".
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Analysis
by VulDB Data Team • 12/21/2019
The vulnerability identified as CVE-2017-9708 represents a critical race condition flaw within the camera driver subsystem of Android devices utilizing the Linux kernel. This issue affects multiple Android variants including MSM, Firefox OS for MSM, and QRD Android platforms, specifically targeting devices that incorporate the Linux kernel from Code Aurora Forum. The flaw manifests in the msm_ois_power_down function which operates without proper mutex protection, creating an environment where concurrent access to shared resources can lead to unpredictable behavior and system instability.
The technical root cause of this vulnerability lies in the improper synchronization mechanism within the camera driver's power management functions. When the msm_ois_power_down function is invoked, it directly accesses the "*reg_ptr" variable within the msm_camera_config_single_vreg subfunction without acquiring the necessary mutex locks. This race condition allows multiple threads or processes to simultaneously modify the same memory location, potentially leading to data corruption, memory access violations, or arbitrary code execution. The vulnerability is classified under CWE-362, which specifically addresses Race Conditions, and represents a classic example of improper locking mechanisms in concurrent programming environments.
The operational impact of this vulnerability extends beyond simple system instability to potentially compromise the integrity of the device's camera functionality and overall security posture. Attackers could exploit this race condition to manipulate camera driver operations, potentially gaining unauthorized access to camera hardware or injecting malicious code into the system. The vulnerability affects devices running Android releases from CAF that utilize the Linux kernel, making it widespread across numerous mobile platforms. This flaw can be leveraged in various attack scenarios including privilege escalation, denial of service conditions, and potential data exfiltration from camera-related operations.
Mitigation strategies for CVE-2017-9708 should focus on implementing proper mutex synchronization within the affected functions. Security patches must ensure that the msm_ois_power_down function properly acquires and releases mutex locks before accessing shared variables like "*reg_ptr". Additionally, code reviews should enforce strict adherence to concurrent programming best practices and proper resource management protocols. Organizations should prioritize updating affected devices to patched versions that address the race condition through proper locking mechanisms. The ATT&CK framework categorizes this vulnerability under privilege escalation and defense evasion techniques, as it can be used to manipulate system functions and potentially bypass security controls. Device manufacturers and security teams should implement comprehensive testing procedures to verify that mutex locks are properly implemented and that concurrent access to shared resources is adequately protected against race conditions.