CVE-2016-8389 in Argus
Summary
by MITRE
An exploitable integer-overflow vulnerability exists within Iceni Argus. When it attempts to convert a malformed PDF to XML, it will attempt to convert each character from a font into a polygon and then attempt to rasterize these shapes. As the application attempts to iterate through the rows and initializing the polygon shape in the buffer, it will write outside of the bounds of said buffer. This can lead to code execution under the context of the account running it.
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Analysis
by VulDB Data Team • 09/02/2020
The CVE-2016-8389 vulnerability represents a critical integer overflow flaw in Iceni Argus software that specifically manifests during PDF to XML conversion processes. This vulnerability operates within the context of document processing applications and demonstrates how seemingly benign file format conversions can expose fundamental memory management weaknesses. The flaw occurs when the application processes malformed PDF files that contain specially crafted font data, triggering a cascade of memory manipulation errors that ultimately enable remote code execution. The vulnerability is particularly concerning because it operates at the intersection of document rendering and memory allocation, where improper bounds checking creates opportunities for attackers to manipulate application behavior through carefully constructed input files.
The technical implementation of this vulnerability involves the application's handling of font character data during PDF processing. When Iceni Argus encounters a malformed PDF, it attempts to convert each character from a font into polygonal representations for XML conversion purposes. During this conversion process, the application iterates through rows of character data and attempts to initialize polygon shapes within a predetermined buffer space. The integer overflow occurs when the application calculates memory requirements for polygon storage, resulting in an overflow condition that causes subsequent memory writes to occur outside the allocated buffer boundaries. This memory corruption directly violates standard software security practices and creates opportunities for attackers to manipulate program execution flow through carefully crafted input sequences.
The operational impact of this vulnerability extends beyond simple memory corruption to encompass full system compromise under the privileges of the running application. Since the vulnerability enables code execution within the context of the account running Iceni Argus, attackers can potentially escalate privileges depending on the application's execution environment and user permissions. The vulnerability's exploitability is enhanced by the fact that it requires only a malformed PDF file to trigger, making it accessible through various attack vectors including email attachments, web downloads, or file sharing systems. This characteristic aligns with common attack patterns documented in the attack mitigation framework, where input validation failures create persistent security weaknesses that can be exploited repeatedly without requiring additional reconnaissance or privilege escalation efforts.
From a cybersecurity perspective, this vulnerability maps directly to CWE-190, which describes integer overflow conditions that can lead to memory corruption and arbitrary code execution. The flaw also aligns with several ATT&CK tactics including TA0002 (Execution) and TA0005 (Defense Evasion) as attackers can leverage the vulnerability to execute malicious code and potentially bypass security controls. The vulnerability's characteristics demonstrate how legacy document processing systems often contain outdated memory management practices that fail to account for modern security requirements. Organizations utilizing Iceni Argus should implement immediate mitigations including input validation for PDF files, application sandboxing, and network segmentation to prevent exploitation of this vulnerability. Additionally, the vulnerability underscores the importance of regular security updates and vulnerability assessments for document processing software, as these applications frequently handle untrusted input from diverse sources and represent common attack surfaces in enterprise environments.
The remediation approach for CVE-2016-8389 requires immediate patching of the Iceni Argus software to address the integer overflow condition in buffer management. System administrators should also implement network-based controls to filter PDF files at ingress points and consider deploying application whitelisting solutions to restrict execution of vulnerable software. Regular vulnerability scanning and penetration testing should include assessment of document processing applications to identify similar memory corruption vulnerabilities. The vulnerability serves as a reminder of the critical importance of proper bounds checking in memory management operations and demonstrates how seemingly simple operations like font rendering can expose complex security weaknesses when not properly validated against malicious input conditions.