CVE-2018-11683 in Liblouis
Summary
by MITRE
Liblouis 3.5.0 has a stack-based Buffer Overflow in the function parseChars in compileTranslationTable.c, a different vulnerability than CVE-2018-11440.
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Analysis
by VulDB Data Team • 03/21/2023
The vulnerability identified as CVE-2018-11683 represents a critical stack-based buffer overflow within the Liblouis braille translation library version 3.5.0. This library serves as a fundamental component for braille translation and formatting across numerous applications and systems, making the discovery of such a vulnerability particularly concerning for accessibility software ecosystems. The flaw specifically manifests within the parseChars function located in the compileTranslationTable.c source file, indicating a core processing mechanism responsible for handling character data during translation table compilation.
The technical nature of this buffer overflow stems from inadequate input validation and bounds checking within the parseChars function. When processing certain malformed or excessively long character sequences, the function fails to properly constrain buffer allocations, allowing attacker-controlled data to overwrite adjacent stack memory locations. This vulnerability classifies under CWE-121 Stack-based Buffer Overflow, which occurs when a program writes data beyond the boundaries of a fixed-length stack buffer. The flaw is distinct from CVE-2018-11440, suggesting that multiple vulnerabilities exist within the same library version, each requiring separate remediation approaches.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as stack-based buffer overflows can potentially enable arbitrary code execution when properly exploited. Attackers could craft malicious braille translation files or input data that, when processed by vulnerable applications, would trigger the buffer overflow condition. This could lead to complete system compromise, especially when the affected Liblouis library is used in server applications or environments where untrusted input is processed. The vulnerability affects any system utilizing Liblouis 3.5.0 for braille translation services, including accessibility tools, document processing applications, and educational software platforms that rely on braille generation capabilities.
Mitigation strategies for CVE-2018-11683 should prioritize immediate patching of affected systems with the corrected Liblouis version that addresses this specific buffer overflow vulnerability. Organizations should conduct comprehensive inventory assessments to identify all systems utilizing the vulnerable library version and implement proper input sanitization measures for any braille translation processing functions. Security teams should also consider implementing application whitelisting and input validation controls to prevent exploitation attempts, while monitoring for potential exploitation attempts through network traffic analysis and system logs. The ATT&CK framework categorizes this vulnerability under T1059 Command and Scripting Interpreter and T1203 Exploitation for Client Execution, highlighting the need for both defensive and detection measures to protect against potential exploitation of this stack-based buffer overflow condition.