CVE-2020-0191 in Android
Summary
by MITRE
In ih264d_update_default_index_list() of ih264d_dpb_mgr.c, there is a possible out of bounds read due to a logic error. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-10Android ID: A-140561484
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Analysis
by VulDB Data Team • 06/12/2020
The vulnerability identified as CVE-2020-0191 resides within the ih264d_update_default_index_list function in the ih264d_dpb_mgr.c source file of Android's media processing subsystem. This flaw manifests as a potential out-of-bounds read condition that arises from a logic error in the handling of video decoding operations. The issue specifically affects the H.264 video decoder component that processes multimedia content within the Android operating system. The vulnerability is particularly concerning because it can be exploited to achieve remote information disclosure without requiring any additional execution privileges, making it accessible to attackers who can remotely influence the target system. The Android security patch level A-140561484 indicates this vulnerability was addressed in Android 10 releases, highlighting the severity of the issue.
The technical root cause of this vulnerability stems from improper bounds checking within the video decoding pipeline where the decoder fails to validate array indices before accessing memory locations. When processing H.264 video streams, the decoder maintains a default index list for managing decoded picture buffers, and the logic error in ih264d_update_default_index_list function allows for invalid memory access patterns. This type of vulnerability falls under CWE-129, which specifically addresses insufficient bounds checking, and represents a classic example of how improper input validation can lead to memory safety issues. The flaw occurs during the decoding process when the system attempts to update the default index list without proper validation of the indices being accessed, potentially causing the decoder to read beyond allocated memory boundaries.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential attack surface for remote exploitation. Attackers can craft malicious H.264 video content that, when processed by an affected Android device, triggers the out-of-bounds read condition. This condition can result in the disclosure of sensitive information from the device's memory, including potentially confidential data from other processes or system components. The requirement for user interaction suggests that exploitation typically occurs through user engagement with malicious media content, such as opening compromised video files or visiting malicious web pages that contain crafted video streams. This vulnerability aligns with ATT&CK technique T1059.007 for scripting and T1566.001 for spearphishing attachments, as it represents a common vector for remote code execution through media processing vulnerabilities.
Mitigation strategies for CVE-2020-0191 primarily focus on applying the relevant Android security patches and updates that address the underlying logic error in the video decoding component. Organizations should ensure all Android 10 devices are updated to the latest security patch levels, particularly those containing the fix for Android ID A-140561484. System administrators should also consider implementing network-level filtering to restrict access to potentially malicious media content, though this approach provides only partial protection as the vulnerability can be exploited through various vectors including email attachments and web-based content. Additionally, monitoring for unusual memory access patterns and implementing robust input validation for all media processing components can help detect and prevent exploitation attempts. The fix implemented by Google addresses the specific bounds checking issue in the ih264d_dpb_mgr.c file and reinforces the importance of proper memory management in multimedia processing systems, aligning with security best practices outlined in the OWASP Top Ten and NIST Cybersecurity Framework.