CVE-2020-0495 in Android
Summary
by MITRE • 12/15/2020
In decode_Huffman of JBig2_SddProc.cpp, there is a possible out of bounds write due to an integer overflow. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-155473137
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Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0495 represents a critical security flaw within the Android operating system's JBig2 decoding implementation. This issue manifests in the decode_Huffman function located within JBig2_SddProc.cpp, where an integer overflow condition creates opportunities for out-of-bounds memory writes. The vulnerability specifically affects Android 11 systems and is catalogued under Android ID A-155473137, demonstrating the severity and widespread impact potential of such flaws in mobile operating systems.
The technical root cause of this vulnerability stems from improper handling of integer arithmetic within the Huffman decoding process used for JBig2 image format processing. When processing certain malformed JBig2 data streams, the integer overflow condition allows attackers to manipulate memory access patterns beyond the intended buffer boundaries. This occurs during the decompression phase where Huffman codes are decoded, creating a scenario where calculated memory offsets exceed the allocated buffer limits. The vulnerability falls under CWE-190, which specifically addresses integer overflow conditions, and represents a classic example of how mathematical operations in security-sensitive code can lead to memory corruption vulnerabilities.
From an operational perspective, this vulnerability presents a significant risk for local information disclosure attacks without requiring any special privileges or user interaction for exploitation. The nature of the flaw means that an attacker could potentially access sensitive memory contents through the out-of-bounds write condition, potentially exposing confidential data stored in adjacent memory regions. The vulnerability's impact extends beyond simple data exposure, as it could potentially serve as a stepping stone for more sophisticated attacks, particularly when combined with other exploitation techniques. The fact that no user interaction is required makes this vulnerability particularly dangerous in environments where users may encounter malicious JBig2 content through various channels including email attachments, web browsing, or file downloads.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and information gathering. The local information disclosure capability suggests potential use in reconnaissance phases where attackers seek to understand system memory layouts or extract sensitive data from running processes. Security professionals should consider this vulnerability as part of a broader threat landscape where image format parsing errors can lead to serious security implications. The vulnerability's classification as a local information disclosure threat means that organizations should implement comprehensive patch management strategies to ensure all Android 11 devices receive the necessary security updates. Additionally, network monitoring solutions should be configured to detect potential exploitation attempts involving malformed JBig2 content, as this represents a specific attack vector that could be leveraged in targeted campaigns against mobile devices.
Mitigation strategies should prioritize immediate patch deployment through official Android security updates, as the vulnerability exists within core system components that are difficult to isolate or replace. Organizations should also consider implementing network-based content filtering solutions that can detect and block potentially malicious JBig2 content before it reaches end-user devices. The vulnerability highlights the importance of robust input validation and boundary checking in multimedia processing libraries, particularly those handling complex compression formats like JBig2. Security teams should conduct thorough testing of their Android device management policies to ensure rapid deployment of security patches while maintaining operational continuity. Regular security assessments of mobile device environments should include verification of JBig2 processing capabilities and their associated security configurations to prevent exploitation of similar vulnerabilities in other image processing components.