CVE-2021-0325 in Android
Summary
by MITRE • 02/10/2021
In ih264d_parse_pslice of ih264d_parse_pslice.c, there is a possible out of bounds write due to a heap buffer overflow. This could lead to remote code execution with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-8.1 Android-9 Android-10 Android-11Android ID: A-174238784
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 02/27/2021
The vulnerability identified as CVE-2021-0325 represents a critical heap buffer overflow flaw within the H.264 video decoder component of Android systems. This issue resides in the ih264d_parse_pslice function located in the ih264d_parse_pslice.c source file, where improper bounds checking allows for out of bounds memory writes that can be exploited remotely. The vulnerability affects multiple Android versions including 8.1, 9, 10, and 11, making it a widespread concern across the Android ecosystem. The flaw specifically targets the video decoding pipeline that processes H.264 encoded media streams, which are commonly encountered in multimedia applications, web browsing, and streaming services. The vulnerability is classified as a heap buffer overflow under CWE-121, which represents a fundamental memory safety issue where data is written beyond the allocated buffer boundaries in heap memory.
The operational impact of this vulnerability extends beyond simple memory corruption as it provides a pathway for remote code execution without requiring any additional privileges or user interaction beyond the initial exploitation trigger. This means that an attacker could potentially compromise Android devices simply by delivering malicious H.264 encoded media content through various attack vectors such as email attachments, web pages, or malicious applications. The exploitation process would likely involve crafting specially formatted video data that triggers the buffer overflow condition during the parsing of P-slice frames, which are fundamental components of H.264 video streams used for encoding progressive frame data. The vulnerability's classification aligns with ATT&CK technique T1059.007 for command and script interpreter, as successful exploitation would allow for arbitrary code execution within the context of the video decoding process.
The security implications of CVE-2021-0325 are particularly severe given that it affects core multimedia processing functionality that is essential for Android device operation. Users may encounter this vulnerability when viewing standard video content, making it extremely difficult to defend against through simple user behavior changes. The vulnerability's exploitation requires only a single interaction with malicious content, which can occur through various delivery mechanisms including web browsing, email attachments, or multimedia applications. This makes the vulnerability particularly dangerous in mobile environments where users frequently interact with untrusted content. The Android ID A-174238784 indicates this vulnerability was properly tracked and addressed by Google's security team, though the window of exposure for devices not yet patched remains significant. The issue demonstrates the critical importance of proper memory bounds checking in multimedia codecs and highlights the potential for remote code execution vulnerabilities in widely used software components.
Mitigation strategies for this vulnerability should focus on immediate patch deployment as provided by Google through Android security updates, which typically include memory safety improvements and bounds checking enhancements. Organizations should prioritize patch management processes to ensure all affected Android devices receive the necessary security updates promptly. Additionally, network-level controls such as content filtering and sandboxing of multimedia content can provide additional defense-in-depth measures. The vulnerability serves as a reminder of the critical need for secure coding practices in multimedia processing components and the importance of thorough code reviews for buffer handling operations. Security teams should also consider implementing monitoring for unusual video processing activity that might indicate exploitation attempts, though such monitoring would be limited by the nature of the vulnerability occurring within legitimate media processing functions.