CVE-2017-12443 in minidjvu
Summary
by MITRE
The mdjvu_bitmap_pack_row function in base/4bitmap.c in minidjvu 0.8 can cause a denial of service (invalid memory read and application crash) via a crafted djvu file.
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Analysis
by VulDB Data Team • 06/23/2024
The vulnerability identified as CVE-2017-12443 resides within the minidjvu 0.8 library, specifically in the mdjvu_bitmap_pack_row function located in base/4bitmap.c. This flaw represents a critical security issue that can be exploited through maliciously crafted djvu files, leading to system instability and potential denial of service conditions. The vulnerability manifests when the application processes malformed input data, causing invalid memory read operations that ultimately result in application crashes and system termination.
This technical flaw constitutes a classic buffer over-read condition that falls under CWE-125, which describes out-of-bounds read vulnerabilities where programs access memory locations beyond the intended buffer boundaries. The vulnerability occurs during the bitmap processing phase of djvu file interpretation, where the mdjvu_bitmap_pack_row function fails to properly validate input parameters before attempting to pack bitmap rows. When confronted with crafted djvu files containing malformed data structures, the function attempts to read memory locations that are either uninitialized or outside the allocated buffer boundaries, triggering segmentation faults and application termination.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged by attackers to disrupt services and potentially gain unauthorized access to systems that rely on minidjvu for document processing. Systems utilizing this library for djvu file handling, including document management systems, web applications, and content processing platforms, become susceptible to denial of service attacks. The vulnerability is particularly concerning in environments where automated processing of user-uploaded content occurs, as malicious actors can craft specific djvu files designed to exploit this flaw and cause system-wide disruptions. Network-based attacks can be executed by simply providing the malicious file to any system that processes djvu documents through the vulnerable minidjvu library.
Security professionals should consider this vulnerability in the context of the attack chain described in the MITRE ATT&CK framework, particularly under the T1499 category related to network denial of service attacks. The exploitability of this vulnerability can be enhanced when combined with other attack vectors, such as web application exploitation or file upload functionality abuse. Mitigation strategies should include immediate patching of the minidjvu library to version 0.12 or later, which contains the necessary fixes for this memory access violation. Organizations should also implement input validation measures and sanitize all djvu file uploads through content inspection tools that can detect and block potentially malicious files before they reach the vulnerable processing functions.
Additional protective measures include implementing network segmentation to limit access to systems processing djvu files, deploying intrusion detection systems that can identify suspicious file upload patterns, and establishing robust monitoring protocols for service availability. The vulnerability highlights the importance of proper input validation and memory management in document processing libraries, as similar issues can occur in other multimedia processing components. Regular security assessments of third-party libraries and maintaining up-to-date software versions should be standard practices to prevent exploitation of such vulnerabilities. The affected systems should also implement proper error handling mechanisms that prevent crash conditions from leading to system instability or information disclosure, as the invalid memory reads could potentially expose sensitive data through memory dumps or crash information.