CVE-2015-7057 in Xcode
Summary
by MITRE
otools in Apple Xcode before 7.2 allows local users to gain privileges or cause a denial of service (memory corruption) via a crafted mach-o file, a different vulnerability than CVE-2015-7049.
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Analysis
by VulDB Data Team • 05/14/2018
The vulnerability identified as CVE-2015-7057 affects the otools component within Apple Xcode versions prior to 7.2, representing a critical security flaw that enables local attackers to escalate privileges or induce denial of service conditions through manipulation of Mach-O executable files. This vulnerability specifically targets the object file processing capabilities of Xcode's toolchain, exploiting weaknesses in how the system handles binary file formats that are fundamental to macOS and iOS application development. The flaw demonstrates the inherent risks associated with complex toolchain components that process untrusted input from developers during the software compilation and linking phases.
The technical implementation of this vulnerability stems from insufficient validation and sanitization of Mach-O file structures within the otools utility. When Xcode processes a crafted Mach-O file, the otools component fails to properly validate the file headers, section structures, or relocation entries, leading to memory corruption issues that can be exploited to execute arbitrary code with elevated privileges. This memory corruption occurs during the object file linking and processing stages where the toolchain attempts to parse and organize the binary data for compilation. The vulnerability operates at the intersection of software development toolchain security and operating system privilege management, creating a pathway for local attackers to leverage their presence on a development machine to gain system-level access. The flaw is categorized under CWE-121, heap-based buffer overflow, and represents a classic example of how development tools can become attack vectors when not properly secured against malformed input.
The operational impact of CVE-2015-7057 extends beyond simple privilege escalation to encompass broader development environment compromise and potential supply chain attacks. Since Xcode is widely used by developers for creating applications for Apple's platforms, a compromised development machine could result in malicious code injection into legitimate applications, affecting millions of end users. The vulnerability particularly threatens organizations that maintain development environments with multiple users or those that do not regularly update their Xcode installations. Attackers could exploit this weakness to install persistent backdoors on developer machines, potentially compromising entire development workflows. The memory corruption aspect also means that systems could experience unexpected crashes or system instability, leading to denial of service conditions that disrupt legitimate development activities. This vulnerability aligns with ATT&CK technique T1059.001 for execution through command and scripting interpreter, and T1546.008 for persistence through root cause analysis and system modification.
Organizations should immediately implement mandatory Xcode updates to version 7.2 or later to remediate this vulnerability, as Apple released patches specifically addressing the Mach-O file processing flaws in this update. System administrators should conduct comprehensive inventory checks to identify all systems running vulnerable Xcode versions and implement automated patch management solutions to prevent future occurrences. Development teams should establish secure coding practices for handling external binaries and consider implementing sandboxing mechanisms around development toolchains to limit potential impact. The vulnerability highlights the importance of securing development environments and demonstrates that even seemingly benign tools like compilers and linkers can become significant security risks when not properly hardened against malformed input. Regular security assessments of development toolchains should be integrated into organizational security protocols to identify similar vulnerabilities in other build tools and development utilities.