CVE-2018-6641 in MathType
Summary
by MITRE
An Arbitrary Free (Remote Code Execution) issue was discovered in Design Science MathType 6.9c. Crafted input can overwrite a structure, leading to a function call with an invalid parameter, and a subsequent free of important data such as a function pointer or list pointer. This is fixed in 6.9d.
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Analysis
by VulDB Data Team • 01/09/2020
The vulnerability identified as CVE-2018-6641 represents a critical arbitrary free condition within Design Science MathType version 6.9c, which can be exploited to achieve remote code execution. This flaw exists in the handling of crafted input data that allows attackers to manipulate memory structures during processing. The vulnerability stems from improper validation of user-supplied data when parsing mathematical expressions or formulae within the MathType application. When malicious input is processed, it can cause the application to free memory locations that contain critical function pointers or list pointers, leading to potential code execution capabilities.
The technical implementation of this vulnerability aligns with CWE-459, which describes incomplete cleanup issues that can result in memory corruption and arbitrary code execution. The flaw manifests when the application processes malformed input that triggers an invalid memory free operation, potentially causing the program to execute arbitrary code with the privileges of the affected application. This arbitrary free condition creates a scenario where attackers can manipulate the program's memory layout to redirect execution flow through corrupted function pointers or list structures. The vulnerability is particularly dangerous because it allows for remote code execution without requiring local system access, making it a significant threat to systems running affected versions of MathType.
The operational impact of CVE-2018-6641 extends beyond simple remote code execution to encompass potential privilege escalation and system compromise. Attackers can leverage this vulnerability to execute malicious code on targeted systems, potentially establishing persistent backdoors or exfiltrating sensitive data. The vulnerability affects any system where MathType 6.9c is installed and actively processes user input, including office environments, educational institutions, and enterprise networks. Given that MathType is commonly used in document processing and mathematical content creation, the attack surface is broad and includes various file types that may contain embedded mathematical expressions. The remote nature of the exploitation means that attackers can target vulnerable systems from external networks without requiring physical access or local credentials.
Security mitigations for this vulnerability include immediate upgrade to Design Science MathType version 6.9d, which contains the necessary patches to address the arbitrary free condition. Organizations should implement network segmentation and access controls to limit exposure of systems running MathType, particularly in environments where untrusted input processing occurs. Additionally, deploying intrusion detection systems with signatures for known exploit patterns and monitoring for unusual memory allocation or deallocation patterns can help detect exploitation attempts. The vulnerability demonstrates the importance of proper memory management practices and input validation in preventing arbitrary free conditions that can lead to remote code execution. Security teams should also consider implementing application whitelisting policies to restrict execution of untrusted MathType processing components and maintain regular vulnerability assessments to identify similar memory corruption issues in other software applications.