CVE-2017-13742 in Liblouis
Summary
by MITRE
There is a stack-based buffer overflow in Liblouis 3.2.0, triggered in the function includeFile() in compileTranslationTable.c, that will lead to a remote denial of service attack.
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Analysis
by VulDB Data Team • 12/27/2022
The vulnerability identified as CVE-2017-13742 represents a critical stack-based buffer overflow within Liblouis version 3.2.0, a widely-used braille translation library that converts text to braille and vice versa. This flaw exists specifically within the includeFile() function located in the compileTranslationTable.c source file, making it a prime target for exploitation by malicious actors seeking to disrupt services. The library serves as a foundational component for numerous accessibility applications and systems that rely on braille conversion capabilities, thereby amplifying the potential impact of this vulnerability across multiple software ecosystems. The buffer overflow occurs when the function processes include directives in translation tables, where insufficient input validation allows attackers to craft maliciously formatted files that exceed allocated stack buffer boundaries. This particular vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory safety issue that has been consistently identified as one of the most prevalent attack vectors in software security. The flaw enables remote code execution capabilities through a denial of service attack, where an attacker can send specially crafted translation table files to a vulnerable system, causing the application to crash or become unresponsive.
The operational impact of this vulnerability extends beyond simple service disruption, as it can severely compromise the accessibility services that depend on Liblouis for braille conversion. Systems utilizing this library may include web applications, desktop software, mobile platforms, and server-side services that process braille translation requests. When exploited, the buffer overflow can cause applications to terminate unexpectedly, potentially leading to complete service outages for users who rely on braille accessibility features. The remote nature of the attack means that adversaries can exploit this vulnerability without requiring physical access to the target system, making it particularly dangerous for publicly accessible services. Attackers can leverage this vulnerability to target any application or service that uses Liblouis version 3.2.0 for processing translation tables, including e-learning platforms, document conversion tools, and accessibility software. The vulnerability's exploitation does not necessarily require complex attack vectors, as it can be triggered through standard file processing operations that applications perform when handling translation table includes. This characteristic makes the vulnerability highly attractive to threat actors seeking to cause maximum disruption with minimal effort.
Mitigation strategies for CVE-2017-13742 must focus on immediate remediation through version updates, as the vulnerability has been addressed in subsequent releases of Liblouis where proper bounds checking and input validation have been implemented. Organizations should conduct comprehensive vulnerability assessments to identify all systems using the affected library version and prioritize patching efforts accordingly. Security teams should also implement network monitoring to detect potential exploitation attempts, particularly when processing translation table files from untrusted sources. The remediation process should include not only updating the library but also reviewing and testing applications that depend on Liblouis to ensure compatibility with patched versions. Additional protective measures include implementing strict file validation procedures, limiting file upload capabilities, and employing sandboxing techniques for processing untrusted translation tables. From an operational security perspective, organizations should consider implementing the principle of least privilege when handling translation table files, ensuring that applications process these files with minimal required permissions. The vulnerability also highlights the importance of secure coding practices, particularly in memory management and input validation, which aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1499.004 for network denial of service. Security frameworks should mandate regular library updates and vulnerability scanning to prevent similar issues in future deployments, as this vulnerability demonstrates the persistent risks associated with outdated software components in accessibility and translation systems.