CVE-2022-34873 in Foxit
Summary
by MITRE • 07/18/2022
This vulnerability allows remote attackers to disclose sensitive information on affected installations of Foxit PDF Reader 11.2.1.53537. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of Annotation objects. By performing actions in JavaScript, an attacker can trigger a read past the end of an allocated object. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process. Was ZDI-CAN-16777.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/06/2022
The vulnerability identified as CVE-2022-34873 represents a critical information disclosure flaw in Foxit PDF Reader version 11.2.1.53537 that exposes systems to remote exploitation through carefully crafted PDF documents. This vulnerability falls under the category of buffer over-read conditions, where the application fails to properly validate bounds when processing Annotation objects within PDF files. The flaw specifically manifests during JavaScript execution within the PDF context, where malicious code can manipulate the reading behavior beyond the allocated memory boundaries of annotation data structures. This particular vulnerability demonstrates the inherent risks associated with PDF reader applications that must parse and render complex document elements while executing embedded scripting code.
The technical implementation of this vulnerability stems from improper bounds checking within the Annotation object processing subsystem of Foxit PDF Reader. When a PDF document contains maliciously crafted Annotation objects, the application's JavaScript engine fails to validate array indices or object boundaries before accessing memory locations. This allows an attacker to read data from memory locations that extend beyond the intended object boundaries, potentially exposing sensitive information including memory contents, stack data, or other internal application state. The vulnerability operates at the intersection of memory safety issues and JavaScript execution contexts, creating a pathway where information disclosure can lead to more severe exploitation vectors. This flaw aligns with CWE-125, which describes out-of-bounds read conditions, and represents a classic example of how improper memory validation can create security risks in document processing applications.
The operational impact of CVE-2022-34873 extends beyond simple information disclosure to create potential pathways for more sophisticated attacks. While the primary effect involves reading past the end of allocated objects, this vulnerability can be leveraged as a precursor to privilege escalation or code execution attacks. An attacker who successfully exploits this vulnerability can potentially gather sufficient information to bypass security mitigations such as address space layout randomization or stack canaries. The requirement for user interaction through visiting malicious web pages or opening compromised files means that successful exploitation typically requires social engineering or targeted phishing campaigns. However, once triggered, the vulnerability can provide attackers with enough information to craft more effective subsequent attacks, making it particularly dangerous in enterprise environments where PDF documents are frequently exchanged. This aligns with ATT&CK technique T1059.007 for JavaScript execution and T1068 for local privilege escalation.
Mitigation strategies for CVE-2022-34873 should prioritize immediate patching of affected Foxit PDF Reader installations to the latest available version that addresses this specific memory handling flaw. Organizations should implement network-based controls such as web application firewalls or content filtering systems that can detect and block malicious PDF content before it reaches end users. Additionally, user education and awareness programs should emphasize the dangers of opening untrusted PDF files or visiting suspicious websites that may contain maliciously crafted documents. Security teams should also consider implementing sandboxing mechanisms for PDF processing and monitoring for unusual memory access patterns or information disclosure attempts. The vulnerability demonstrates the importance of robust input validation and memory safety practices in document processing applications, and organizations should review their PDF handling procedures to ensure that similar flaws are not present in other components of their document processing infrastructure. Regular vulnerability assessments and penetration testing should include evaluation of PDF reader applications to identify potential boundary condition issues that could be exploited for information disclosure or privilege escalation attacks.