CVE-2007-0650 in makeindex
Summary
by MITRE
Buffer overflow in the open_sty function in mkind.c for makeindex 2.14 in teTeX might allow user-assisted remote attackers to overwrite files and possibly execute arbitrary code via a long filename. NOTE: other overflows exist but might not be exploitable, such as a heap-based overflow in the check_idx function.
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Analysis
by VulDB Data Team • 07/19/2019
The vulnerability described in CVE-2007-0650 represents a critical buffer overflow condition within the makeindex utility version 2.14 distributed with teTeX, specifically within the open_sty function located in mkind.c. This flaw constitutes a classic stack-based buffer overflow that occurs when processing user-supplied input through filename parameters. The vulnerability arises from insufficient input validation and bounds checking during the handling of index style files, creating an exploitable condition where maliciously crafted filenames can cause memory corruption. The issue is particularly concerning as it allows for user-assisted remote code execution, meaning an attacker does not necessarily need to have direct access to the system but can leverage the vulnerability through manipulated input provided by users.
The technical implementation of this vulnerability involves the open_sty function failing to properly validate the length of input filenames before copying them into fixed-size buffers. When a filename exceeds the allocated buffer space, the excess data overflows into adjacent memory locations, potentially overwriting critical program variables, return addresses, or file descriptors. This memory corruption can lead to arbitrary code execution when the program attempts to return to an overwritten instruction pointer. The vulnerability is classified as a CWE-121 stack-based buffer overflow, which is a well-documented weakness in software development practices where insufficient bounds checking allows attackers to manipulate program execution flow. The heap-based overflow mentioned in the description as potentially existing but non-exploitable suggests additional memory corruption vulnerabilities within the same codebase, specifically in the check_idx function, though these secondary issues may not present the same remote execution capabilities.
The operational impact of this vulnerability extends beyond simple file corruption or denial of service scenarios, as it enables full system compromise when successfully exploited. Attackers can leverage this vulnerability to overwrite critical system files, inject malicious code into running processes, or escalate privileges within the affected environment. The remote aspect of the attack means that an attacker can potentially exploit this vulnerability through network-based delivery mechanisms without requiring physical access to the target system. This makes the vulnerability particularly dangerous in multi-user environments where makeindex is commonly used for document processing, such as in academic institutions, publishing systems, or automated build environments. The vulnerability affects systems using teTeX 2.14 or earlier versions, which were widely deployed in the late 2000s and early 2010s, making it a significant concern for organizations maintaining legacy systems.
Mitigation strategies for this vulnerability should include immediate patching of the makeindex utility to version 2.15 or later, which contains the necessary fixes for the buffer overflow conditions. Organizations should also implement input validation measures at the application level to reject overly long filenames or those containing suspicious characters that could lead to buffer overflows. System administrators should consider implementing privilege separation for makeindex operations, ensuring that the utility runs with minimal necessary permissions. Additionally, network-based defenses such as intrusion detection systems can be configured to monitor for suspicious filename patterns that might indicate exploitation attempts. The vulnerability aligns with several ATT&CK tactics including privilege escalation and execution through the use of vulnerable system utilities, making it a target for comprehensive security hardening efforts. Organizations should also consider implementing automated patch management processes to ensure all instances of teTeX and makeindex are kept current with security updates, as this vulnerability represents a classic example of how insufficient input validation can lead to severe security consequences.