CVE-2018-11963 in Android
Summary
by MITRE
In all android releases(Android for MSM, Firefox OS for MSM, QRD Android) from CAF using the linux kernel, Buffer overread may occur due to non-null terminated strings while processing vsprintf in camera jpeg driver.
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Analysis
by VulDB Data Team • 04/22/2020
The vulnerability identified as CVE-2018-11963 represents a critical buffer overread condition affecting multiple Android variants including MSM-based systems, Firefox OS for MSM, and QRD Android implementations. This issue stems from the Linux kernel components utilized by these platforms and specifically manifests within the camera jpeg driver during vsprintf processing operations. The fundamental flaw occurs when the system processes non-null terminated strings, creating a scenario where memory boundaries are exceeded during string formatting operations.
The technical implementation of this vulnerability involves the improper handling of string termination within the camera driver's jpeg processing pipeline. When vsprintf function is invoked to format string data for jpeg metadata or image processing, the system fails to properly validate that input strings are null-terminated before processing. This oversight allows attackers to craft malicious input that can cause the processing function to read beyond allocated memory boundaries, potentially accessing adjacent memory regions containing sensitive data or system information. The vulnerability is classified under CWE-121 as a stack-based buffer overflow condition, though the specific manifestation as an overread indicates memory access patterns that extend beyond the intended buffer boundaries rather than overwriting stack contents.
From an operational perspective, this vulnerability presents significant security implications for mobile devices running affected Android variants. The camera jpeg driver represents a privileged component that operates with elevated permissions, making successful exploitation potentially devastating for system integrity and user privacy. Attackers could leverage this vulnerability to extract sensitive information from memory, potentially accessing camera metadata, image data, or other system information that could be used for further attacks. The impact extends beyond simple information disclosure as the overread conditions could also lead to system instability or denial of service scenarios that would disrupt normal device operation.
The attack surface for this vulnerability is particularly concerning given that camera drivers typically process untrusted input from various sources including user-generated images and metadata. The exploitation process would likely involve crafting specially formatted jpeg files or camera input data that when processed through the vulnerable driver triggers the buffer overread condition. This aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage, as successful exploitation could enable attackers to execute arbitrary code within the camera driver context. Mitigation strategies should focus on implementing proper string validation and null-termination checks within the vsprintf processing pipeline, along with input sanitization measures that prevent malformed strings from reaching the vulnerable code paths. Additionally, kernel-level memory protection mechanisms and stack canaries should be implemented to detect and prevent exploitation attempts, while regular security updates and patches should be deployed to address the underlying kernel components.