CVE-2015-3864 in Android
Summary
by MITRE
Integer underflow in the MPEG4Extractor::parseChunk function in MPEG4Extractor.cpp in libstagefright in mediaserver in Android before 5.1.1 LMY48M allows remote attackers to execute arbitrary code via crafted MPEG-4 data, aka internal bug 23034759. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-3824.
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Analysis
by VulDB Data Team • 06/12/2024
The vulnerability identified as CVE-2015-3864 represents a critical integer underflow flaw within the Android media processing framework that has significant implications for mobile device security. This vulnerability resides in the MPEG4Extractor::parseChunk function located in the MPEG4Extractor.cpp file within the libstagefright library of the Android mediaserver component. The flaw specifically affects Android versions prior to 5.1.1 LMY48M, making it a widespread concern across numerous mobile devices that were vulnerable to remote code execution attacks. The vulnerability was originally documented as internal bug 23034759, indicating its discovery within Google's internal security tracking systems and highlighting the severity of the issue.
The technical nature of this vulnerability stems from improper handling of integer values during the parsing of MPEG-4 media files, where the application fails to properly validate input data before performing arithmetic operations. When maliciously crafted MPEG-4 data is processed by the vulnerable mediaserver component, the integer underflow condition occurs during the chunk parsing operation, creating a scenario where an attacker can manipulate the memory layout and potentially execute arbitrary code with the privileges of the mediaserver process. This type of vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, specifically manifesting as an integer underflow condition that can be exploited to bypass memory safety mechanisms. The vulnerability is particularly concerning because it operates at the media parsing layer, where it can be triggered by simply opening or processing a maliciously crafted media file without requiring any user interaction or special privileges.
The operational impact of CVE-2015-3864 extends beyond simple remote code execution to encompass potential system compromise and data theft capabilities. Since the mediaserver process typically runs with elevated privileges and has access to various system resources, successful exploitation could allow attackers to gain unauthorized access to device functionality, potentially leading to complete system compromise. The vulnerability's remote nature means that attackers can deliver malicious payloads through various channels including email attachments, web downloads, or multimedia content shared through social media platforms, making it particularly dangerous for widespread deployment. This aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as the vulnerability enables attackers to execute arbitrary commands and potentially escalate their privileges within the Android environment. The fact that this vulnerability was caused by an incomplete fix for CVE-2015-3824 demonstrates the complexity of security patches and the potential for introducing new vulnerabilities during the remediation process.
Mitigation strategies for CVE-2015-3864 primarily focus on immediate system updates and security hardening measures. Organizations and individuals should prioritize updating affected Android devices to version 5.1.1 or later, which contains the complete fix for both CVE-2015-3824 and CVE-2015-3864. System administrators should implement network-level controls to block suspicious media file downloads and consider deploying mobile device management solutions that can automatically apply security patches. Additionally, the vulnerability highlights the importance of proper input validation and bounds checking in media processing libraries, suggesting that developers should implement comprehensive sanitization routines for all external data inputs. Security researchers recommend implementing runtime protections such as address space layout randomization and stack canaries to make exploitation more difficult, while also emphasizing the need for regular security audits of media processing components. The vulnerability serves as a reminder of the critical importance of thorough testing during security patch development and the potential consequences of incomplete fixes, as the remediation for this vulnerability required a complete rework of the integer validation logic rather than a simple code correction.