CVE-2019-1987 in Android
Summary
by MITRE
In onSetSampleX of SkSwizzler.cpp, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution with no additional execution privileges needed. User interaction is needed for exploitation. Product: Android. Versions: Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9. Android ID: A-118143775.
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Analysis
by VulDB Data Team • 07/26/2023
The vulnerability described in CVE-2019-1987 resides within the SkSwizzler.cpp component of Android's graphics rendering system, specifically in the onSetSampleX function where a critical out-of-bounds write condition exists due to inadequate input validation. This flaw represents a classic buffer overflow vulnerability that can be exploited to execute arbitrary code remotely without requiring elevated privileges. The vulnerability affects multiple Android versions including 7.0, 7.1.1, 7.1.2, 8.0, 8.1, and 9.0, indicating a widespread impact across the Android ecosystem. The flaw is categorized under CWE-129 as an insufficient input validation issue, where the system fails to properly validate array indices before performing memory operations.
The technical exploitation of this vulnerability requires user interaction, typically through malicious media files or web content that triggers the affected graphics processing function. When a malicious payload is processed by the graphics subsystem, the missing bounds check allows an attacker to write data beyond the allocated memory buffer, potentially overwriting adjacent memory locations including function pointers or return addresses. This memory corruption can be leveraged to redirect execution flow and ultimately achieve remote code execution. The vulnerability aligns with ATT&CK technique T1059.007 for execution through scripting and T1203 for exploitation for execution through malicious content delivery.
The operational impact of this vulnerability extends beyond simple privilege escalation as it can be weaponized to compromise entire Android devices through seemingly benign user interactions. Attackers can craft malicious images, videos, or web content that when viewed or processed by the affected Android versions will trigger the buffer overflow condition. The lack of additional execution privileges required makes this particularly dangerous as it can be exploited in phishing campaigns or malicious app distributions. The vulnerability demonstrates how graphics processing components can serve as attack vectors for remote code execution, highlighting the importance of memory safety in multimedia processing libraries.
Mitigation strategies for this vulnerability include applying the latest Android security patches from Google, which typically involve implementing proper bounds checking in the onSetSampleX function to validate array indices before memory operations. Organizations should also implement network-based protections such as content filtering and sandboxing mechanisms to prevent users from accessing malicious content that could trigger this vulnerability. Additionally, users should be educated about the risks of interacting with untrusted media files and websites, as the exploitation requires user interaction to be successful. The fix should include comprehensive input validation and memory boundary checks that align with secure coding practices recommended by the CWE guidelines for preventing buffer overflow conditions.