CVE-2024-9253 Overview
CVE-2024-9253 is an out-of-bounds read vulnerability [CWE-125] in Foxit PDF Reader and Foxit PDF Editor on Windows. The flaw resides in the handling of AcroForms, where the application fails to properly validate user-supplied data before reading from an allocated buffer. Remote attackers can exploit this issue to disclose sensitive process memory. Exploitation requires user interaction, such as opening a malicious PDF or visiting a page that serves crafted content. Attackers can chain this bug with other vulnerabilities to achieve arbitrary code execution in the context of the current process. The issue was reported through the Zero Day Initiative program as ZDI-CAN-24492.
Critical Impact
Successful exploitation leaks memory contents from the Foxit process, enabling attackers to bypass mitigations and pivot to code execution when combined with other flaws.
Affected Products
- Foxit PDF Reader for Windows
- Foxit PDF Editor for Windows
- Installations processing untrusted PDF files containing AcroForm content
Discovery Timeline
- 2024-11-22 - CVE-2024-9253 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-9253
Vulnerability Analysis
The vulnerability affects the AcroForm processing logic within Foxit PDF Reader and Foxit PDF Editor. AcroForms are interactive form elements embedded in PDF documents, defined by the PDF specification and rendered by the reader at open time. When Foxit parses a crafted AcroForm structure, the code reads past the end of a heap-allocated buffer. The out-of-bounds read exposes adjacent memory contents to the attacker-controlled document context.
Information disclosure through out-of-bounds reads is frequently used as a primitive to defeat address space layout randomization (ASLR). Attackers who combine leaked pointers with a separate memory corruption bug can construct reliable exploits. The vulnerability requires local user interaction because the target must open the malicious file or navigate to a page hosting the content.
Root Cause
The root cause is missing validation of user-supplied data during AcroForm parsing. The parser trusts length or index fields taken from the PDF without confirming they remain within the bounds of the allocated buffer. When the calculated offset exceeds the buffer size, the read operation returns adjacent heap data instead of failing safely.
Attack Vector
An attacker crafts a PDF document containing a malformed AcroForm structure. The document is delivered through email, a compromised website, or a file-sharing channel. When the victim opens the file in Foxit PDF Reader or Foxit PDF Editor, the parser triggers the out-of-bounds read. The leaked bytes can be exfiltrated through JavaScript embedded in the PDF or observed side effects during form rendering.
No verified public exploit code is available for CVE-2024-9253. Refer to the Zero Day Initiative Advisory ZDI-24-1305 for technical detail on the affected component.
Detection Methods for CVE-2024-9253
Indicators of Compromise
- PDF files containing malformed or oversized AcroForm dictionaries delivered through email or web downloads
- Foxit PDF Reader or Foxit PDF Editor processes crashing or generating exception telemetry after opening a document
- Unexpected outbound network connections initiated by FoxitPDFReader.exe or FoxitPDFEditor.exe following document open events
Detection Strategies
- Inspect PDF attachments at the mail gateway for anomalous AcroForm structures and embedded JavaScript that reads form field memory
- Monitor endpoint telemetry for Foxit processes exhibiting unusual heap access patterns, child process creation, or memory dump activity
- Correlate document-open events with subsequent process behavior to identify chained exploitation attempts
Monitoring Recommendations
- Enable EDR visibility on Foxit binary paths and log module loads, exception events, and network egress
- Track installed Foxit PDF Reader and Foxit PDF Editor versions across the fleet to identify unpatched hosts
- Alert on PDF documents that combine AcroForm content with embedded JavaScript from untrusted sources
How to Mitigate CVE-2024-9253
Immediate Actions Required
- Update Foxit PDF Reader and Foxit PDF Editor for Windows to the latest patched release per the Foxit Security Bulletins
- Restrict opening PDF documents from untrusted sources until patching is complete
- Disable JavaScript execution inside Foxit PDF Reader and Foxit PDF Editor to reduce chained exploitation risk
Patch Information
Foxit has published fixed versions through the Foxit Security Bulletins page. Administrators should review the bulletin corresponding to CVE-2024-9253 and deploy the referenced Foxit PDF Reader and Foxit PDF Editor builds. Additional technical context is available in the Zero Day Initiative Advisory ZDI-24-1305.
Workarounds
- Disable JavaScript in Foxit through Preferences to reduce the attacker's ability to leak or exfiltrate memory contents
- Configure the Safe Reading Mode option in Foxit to restrict processing of active PDF content
- Route inbound PDF traffic through a sandboxed viewer or content disarm and reconstruction (CDR) solution until patches are applied
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
