CVE-2024-9250: Foxit PDF Editor Use-After-Free Vulnerability

CVE-2024-9250 Overview

CVE-2024-9250 is a use-after-free vulnerability [CWE-416] in Foxit PDF Reader and Foxit PDF Editor. The flaw resides in the handling of AcroForms, where the application performs operations on an object without validating that the object still exists. An attacker can leverage this issue to execute arbitrary code in the context of the current process. Exploitation requires user interaction: the target must open a crafted PDF file or visit a malicious page that serves one. The issue was reported through the Zero Day Initiative as ZDI-CAN-24489 and tracked in advisory ZDI-24-1303.

Critical Impact
Successful exploitation grants arbitrary code execution in the context of the user running Foxit PDF Reader or Foxit PDF Editor on Windows.

Affected Products

Foxit PDF Reader (Windows)
Foxit PDF Editor (Windows)
Refer to the Foxit Security Bulletins for exact vulnerable version ranges

Discovery Timeline

2024-11-22 - CVE-2024-9250 published to NVD
2026-06-17 - Last updated in NVD database
Reported to Foxit through the Zero Day Initiative as ZDI-CAN-24489 (ZDI-24-1303)

Technical Details for CVE-2024-9250

Vulnerability Analysis

The vulnerability is a use-after-free condition in the AcroForm subsystem of Foxit PDF Reader and Foxit PDF Editor. AcroForms allow PDF documents to embed interactive form fields with associated JavaScript and object references. During processing of a crafted AcroForm, the application accesses an object that has already been freed, producing dangling pointer use. An attacker who controls the layout of the freed memory can steer subsequent operations to attacker-supplied data, achieving arbitrary code execution in the current process context. The attack requires local file access or user-initiated navigation, which aligns with the local attack vector and required user interaction characteristics reported for this issue.

Root Cause

The root cause is the absence of a validity check on the target object before AcroForm processing performs operations against it. The parser or scripting layer frees an object as part of normal document processing, but a reference to that object persists and is later dereferenced. This condition maps to [CWE-416] Use After Free.

Attack Vector

Exploitation requires the victim to open a malicious PDF document in Foxit PDF Reader or Foxit PDF Editor, or to visit a page that delivers the document to the vulnerable client. The malicious document embeds AcroForm content and, in typical exploitation of this class, JavaScript that manipulates form objects to trigger the free while retaining a reference. Because no verified public proof-of-concept has been published, refer to the Zero Day Initiative advisory ZDI-24-1303 for additional technical context.

Detection Methods for CVE-2024-9250

Indicators of Compromise

Unexpected child processes spawned by FoxitPDFReader.exe or FoxitPDFEditor.exe, particularly command interpreters, script hosts, or rundll32.exe.
Crashes in Foxit processes referencing AcroForm modules, followed by suspicious file writes under user-writable paths.
Inbound PDF documents delivered via email or web download that contain AcroForm structures with embedded JavaScript targeting form field objects.

Detection Strategies

Hunt for process-lineage anomalies where a Foxit process is the parent of cmd.exe, powershell.exe, wscript.exe, or network-capable binaries.
Alert on Foxit processes performing outbound network connections to non-Foxit infrastructure shortly after opening a document.
Inspect PDF attachments at the mail gateway for AcroForm objects combined with obfuscated JavaScript referencing form field manipulation.

Monitoring Recommendations

Enable command-line and process-creation logging on Windows endpoints (Sysmon Event ID 1, Security Event ID 4688) to observe Foxit process behavior.
Correlate document open events with subsequent file system and registry writes to detect post-exploitation persistence.
Track Foxit application versions across the fleet and alert when unpatched builds are executed.

How to Mitigate CVE-2024-9250

Immediate Actions Required

Update Foxit PDF Reader and Foxit PDF Editor on Windows to the fixed versions listed in the Foxit Security Bulletins.
Inventory endpoints for vulnerable Foxit installations and prioritize systems that regularly process externally sourced PDF files.
Restrict opening of PDFs from untrusted sources until patched builds are deployed.

Patch Information

Foxit has published fixes through its security bulletins portal. Consult the Foxit Security Bulletins page and the Zero Day Initiative advisory ZDI-24-1303 for the specific fixed version applicable to your deployment.

Workarounds

Disable JavaScript execution in Foxit PDF Reader and Foxit PDF Editor via Preferences > JavaScript to reduce the exploitability of AcroForm scripting flaws.
Enable Safe Reading Mode in Foxit to block unsolicited external actions triggered by PDF content.
Block or quarantine PDF attachments containing AcroForm JavaScript at the email gateway until patching is complete.

bash

# Example: enforce Safe Reading Mode and disable JavaScript via Windows registry
reg add "HKCU\Software\Foxit Software\Foxit PDF Reader\Preferences\JSPrefs" /v "bJSEnabled" /t REG_DWORD /d 0 /f
reg add "HKCU\Software\Foxit Software\Foxit PDF Reader\Preferences\Trust Manager" /v "bSafeReadingMode" /t REG_DWORD /d 1 /f