CVE-2019-0546 in Visual Studio
Summary
by MITRE
A remote code execution vulnerability exists in Visual Studio when the C++ compiler improperly handles specific combinations of C++ constructs, aka "Visual Studio Remote Code Execution Vulnerability." This affects Microsoft Visual Studio.
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Analysis
by VulDB Data Team • 04/26/2020
The vulnerability identified as CVE-2019-0546 represents a critical remote code execution flaw within Microsoft Visual Studio's C++ compiler component. This security weakness arises from improper handling of specific combinations of C++ language constructs during the compilation process, creating a potential attack vector that could be exploited by remote adversaries. The flaw specifically impacts the compiler's ability to process certain code patterns, leading to unpredictable behavior that malicious actors could leverage for unauthorized system access. The vulnerability affects multiple versions of Microsoft Visual Studio, making it a widespread concern for development environments that rely on these tools for software creation and compilation. The nature of this vulnerability is particularly concerning because it exists within the core compilation infrastructure that developers depend upon daily, potentially allowing attackers to execute arbitrary code on systems where Visual Studio is installed.
The technical root cause of CVE-2019-0546 stems from insufficient input validation and improper memory handling within the C++ compiler's parsing and code generation phases. When the compiler encounters specific combinations of C++ constructs such as complex template instantiations, nested expressions, or certain operator overloading scenarios, it fails to properly validate the input parameters before processing them. This inadequate validation leads to buffer overflows, memory corruption, or other exploitable conditions that can be manipulated by attackers to gain control over the affected system. The vulnerability manifests during the compilation process when the compiler attempts to generate machine code from source files containing these problematic construct combinations. According to CWE classification, this vulnerability maps to CWE-121: Stack-based Buffer Overflow, as the improper handling of C++ constructs results in memory corruption that can be exploited to overwrite stack memory locations. The flaw essentially creates a situation where attacker-controlled input can influence the compiler's internal operations, potentially leading to arbitrary code execution.
The operational impact of this vulnerability extends beyond simple compilation failures, as it fundamentally compromises the security of development environments and the integrity of software being built. Attackers could potentially exploit this vulnerability by crafting malicious source code files that, when compiled by Visual Studio, would trigger the remote code execution condition. This scenario becomes particularly dangerous in enterprise environments where multiple developers work with shared code repositories, as a single compromised file could affect numerous systems. The vulnerability also poses risks to automated build systems and continuous integration pipelines that rely on Visual Studio's compiler for software deployment. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, as successful exploitation could allow adversaries to execute arbitrary commands on compromised systems. The impact is further amplified by the fact that many development teams may not immediately patch their Visual Studio installations, creating extended windows of exposure across various organizations.
Mitigation strategies for CVE-2019-0546 require immediate action from organizations utilizing affected Visual Studio versions. The primary recommendation involves applying Microsoft's official security updates and patches that address the compiler's improper handling of specific C++ constructs. Organizations should also implement strict source code review processes and code scanning tools that can identify potentially malicious construct combinations before they reach the compiler. Network segmentation and access controls should be strengthened around development environments to limit potential attack vectors. Additionally, developers should be educated about the risks of compiling untrusted code and encouraged to use secure coding practices that avoid problematic C++ construct combinations. Regular security assessments of development environments and continuous monitoring for unusual compilation activities can help detect potential exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date development toolchains and implementing comprehensive security controls throughout the software development lifecycle to prevent exploitation of compiler-level vulnerabilities.