CVE-2016-8334 in Foxit
Summary
by MITRE
A large out-of-bounds read on the heap vulnerability in Foxit PDF Reader can potentially be abused for information disclosure. Combined with another vulnerability, it can be used to leak heap memory layout and in bypassing ASLR.
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Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2016-8334 represents a critical heap-based out-of-bounds read flaw within Foxit PDF Reader version 8.0.1 and earlier. This issue stems from improper input validation during PDF parsing operations where the application fails to adequately bounds-check memory accesses when processing certain PDF objects. The flaw manifests when the reader encounters malformed or specially crafted PDF content that triggers an unintended memory access pattern beyond allocated heap boundaries. Such vulnerabilities typically arise from insufficient boundary checking mechanisms in memory management routines, creating opportunities for attackers to probe memory contents through controlled data manipulation.
The technical exploitation of this vulnerability leverages the out-of-bounds read condition to access adjacent heap memory regions that contain sensitive information. When the PDF parser encounters malformed data structures, it attempts to read memory locations that extend beyond the intended data boundaries, potentially exposing heap metadata, stack contents, or other sensitive data structures. This memory disclosure capability directly aligns with common attack patterns described in the attack technique matrix under technique T1005 for data from local system and T1059 for command and scripting interpreter. The vulnerability falls under CWE-125 which specifically addresses out-of-bounds read conditions, making it a prime candidate for exploitation in advanced persistent threat scenarios.
The operational impact of CVE-2016-8334 extends beyond simple information disclosure, as it provides attackers with crucial insights into memory layout structures that are essential for bypassing modern security mitigations. When combined with other vulnerabilities present in the same application or system, this heap memory leak can reveal the base addresses of heap regions, which directly undermines address space layout randomization ASLR protections. This information disclosure capability enables attackers to craft more sophisticated exploits that can reliably target specific memory locations, effectively nullifying the protective benefits of ASLR. The vulnerability's exploitation potential increases significantly when paired with information leak techniques that allow for precise memory address determination, making it particularly dangerous in targeted attack scenarios.
Mitigation strategies for this vulnerability require immediate patching of the Foxit PDF Reader application to the latest version that contains memory bounds checking improvements and input validation enhancements. System administrators should implement comprehensive monitoring for suspicious PDF file handling activities and consider deploying application whitelisting solutions to restrict execution of potentially malicious PDF content. Security teams should also implement memory protection mechanisms such as heap randomization and stack canaries to add additional layers of defense. The vulnerability demonstrates the importance of proper memory management practices in security-critical applications and aligns with industry best practices outlined in the OWASP Top Ten and NIST Cybersecurity Framework. Organizations should conduct thorough security assessments of their PDF processing workflows and implement network segmentation to limit the potential impact of successful exploitation attempts.