CVE-2018-6640 in MathType
Summary
by MITRE
A Heap Overflow (Remote Code Execution) issue was discovered in Design Science MathType 6.9c. Crafted input can modify the next pointer of a linked list. This is fixed in 6.9d.
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Analysis
by VulDB Data Team • 01/09/2020
The vulnerability identified as CVE-2018-6640 represents a critical heap overflow condition affecting Design Science MathType version 6.9c that can potentially lead to remote code execution. This flaw exists within the software's handling of crafted input data that specifically targets the manipulation of linked list structures. The vulnerability stems from insufficient bounds checking and memory management practices during the processing of user-supplied data that gets parsed into memory structures. The heap overflow occurs when malicious input modifies the next pointer of a linked list node, which subsequently leads to unpredictable memory corruption and potential arbitrary code execution capabilities.
The technical implementation of this vulnerability involves the exploitation of memory corruption through pointer manipulation within heap-allocated structures. When MathType processes malformed input, the software fails to validate the integrity of linked list pointers, allowing an attacker to overwrite adjacent memory locations including critical metadata such as the next pointer of adjacent nodes. This type of vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and specifically relates to CWE-787, representing out-of-bounds write vulnerabilities. The flaw demonstrates characteristics consistent with heap corruption patterns that enable attackers to manipulate program execution flow through controlled memory overwrite operations.
The operational impact of CVE-2018-6640 extends beyond simple memory corruption to encompass full remote code execution capabilities within the context of the vulnerable application. An attacker capable of sending crafted input to a system running MathType 6.9c could potentially execute arbitrary code with the privileges of the affected application, which typically runs with elevated permissions. This vulnerability affects users who process untrusted documents containing malicious MathType content, making it particularly dangerous in environments where document exchange occurs frequently. The attack vector typically involves email attachments, web-based document sharing, or collaborative editing platforms where MathType content is embedded. The vulnerability's exploitation aligns with ATT&CK technique T1059, specifically focusing on command and scripting interpreter usage, as successful exploitation would likely involve executing malicious code within the application's execution context.
Mitigation strategies for this vulnerability center on immediate software updates to version 6.9d, which contains the necessary patches to prevent the heap overflow condition. Organizations should implement comprehensive patch management procedures to ensure all instances of MathType are updated promptly. Additional protective measures include deploying application whitelisting policies that restrict execution of untrusted MathType content, implementing network segmentation to limit exposure, and establishing monitoring procedures for unusual memory allocation patterns. Security teams should also consider implementing sandboxing techniques for document processing and conducting regular vulnerability assessments of installed software versions. The fix in version 6.9d addresses the root cause by implementing proper bounds checking and pointer validation mechanisms that prevent the modification of critical linked list metadata structures during input processing.