CVE-2012-6535 in DjVuLibre
Summary
by MITRE
DjVuLibre before 3.5.25.3, as used in Evince, Sumatra PDF Reader, VuDroid, and other products, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted DjVu (aka .djv) file.
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Analysis
by VulDB Data Team • 12/28/2024
The vulnerability identified as CVE-2012-6535 represents a critical memory corruption flaw affecting DjVuLibre versions prior to 3.5.25.3. This issue impacts multiple widely-used document viewing applications including Evince, Sumatra PDF Reader, and VuDroid, creating a significant attack surface across various operating systems and platforms. The vulnerability stems from inadequate input validation and memory management within the DjVu file parsing functionality, which processes documents with the .djv extension. When a maliciously crafted DjVu file is processed by any affected application, the flaw can trigger unpredictable behavior ranging from arbitrary code execution to system crashes and denial of service conditions.
The technical root cause of this vulnerability lies in buffer overflows and improper memory handling within the DjVuLibre library's parsing routines. Attackers can exploit this weakness by constructing specially formatted DjVu files that contain malformed data structures or oversized elements that exceed the allocated memory buffers during file processing. This memory corruption can lead to stack smashing, heap corruption, or other memory management errors that allow attackers to inject and execute malicious code with the privileges of the affected application. The vulnerability is particularly dangerous because DjVu files are commonly used for document sharing and can be encountered in legitimate business and personal contexts, making social engineering attacks more effective.
From an operational perspective, the impact of CVE-2012-6535 extends across multiple threat vectors and attack scenarios. The vulnerability enables remote code execution capabilities that can be leveraged by attackers to gain full control over affected systems, potentially leading to data breaches, system compromise, or lateral movement within network environments. Organizations using affected applications face significant risk exposure since DjVu files can be delivered through email attachments, web downloads, or shared network resources. The denial of service aspect further compounds the threat by allowing attackers to disrupt legitimate document processing workflows and potentially cause system instability. This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and demonstrates characteristics consistent with ATT&CK technique T1059 for command and scripting interpreter usage.
Mitigation strategies for CVE-2012-6535 primarily focus on immediate remediation through software updates and patches. System administrators should prioritize upgrading all affected applications to versions containing the patched DjVuLibre library, specifically ensuring that versions 3.5.25.3 or later are deployed. Organizations should implement network-based controls such as file type filtering and sandboxing mechanisms to prevent processing of DjVu files from untrusted sources. Additionally, security teams should consider deploying intrusion detection systems that can identify suspicious DjVu file patterns and monitor for exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of older software versions within the organization's infrastructure. The vulnerability also underscores the importance of maintaining up-to-date third-party libraries and implementing proper input validation controls in document processing applications to prevent similar issues from occurring in the future.