CVE-2024-25648 Overview
CVE-2024-25648 is a use-after-free vulnerability [CWE-416] in Foxit Reader 2024.1.0.23997 that affects how the application handles ComboBox widgets. A specially crafted JavaScript payload embedded in a malicious PDF document can trigger reuse of a previously freed object. The resulting memory corruption can lead to arbitrary code execution in the context of the user running Foxit Reader. Exploitation requires the victim to open a malicious PDF file or visit a malicious website if the browser plugin extension is enabled. The flaw affects both Windows and macOS builds of Foxit PDF Reader and Foxit PDF Editor.
Critical Impact
Successful exploitation allows attackers to execute arbitrary code on the victim's system through a maliciously crafted PDF or web page.
Affected Products
- Foxit PDF Reader 2024.1.0.23997 on Windows and macOS
- Foxit PDF Editor 2024.1.0.23997 and 2024.1.0.63682
- Foxit Reader browser plugin extension
Discovery Timeline
- 2024-04-30 - CVE-2024-25648 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-25648
Vulnerability Analysis
The vulnerability resides in Foxit Reader's JavaScript engine handling of ComboBox form widgets. When a PDF document contains JavaScript that manipulates a ComboBox widget in a specific sequence, the application frees an internal object while retaining a reference to it. Subsequent operations dereference the dangling pointer, producing a use-after-free condition that can be groomed to overlap attacker-controlled data on the heap.
Attackers can leverage this primitive to achieve memory corruption that culminates in arbitrary code execution under the privileges of the Foxit Reader process. The EPSS score of 15.639% (96.418 percentile) reflects elevated exploit likelihood relative to other published CVEs, though no public exploit code or CISA KEV listing exists at this time.
Root Cause
The root cause is improper lifetime management of ComboBox widget objects exposed to the JavaScript engine. The application releases backing memory while JavaScript references persist, violating the object lifecycle contract between the native widget layer and the scripting layer [CWE-416].
Attack Vector
Exploitation occurs through one of two delivery paths. An attacker can email or host a malicious PDF and rely on the user opening it in Foxit Reader. Alternatively, if the Foxit browser plugin is enabled, simply visiting a crafted webpage that loads the malicious PDF triggers the vulnerability. User interaction is required, but no authentication or local access is needed.
The vulnerability mechanism involves JavaScript actions attached to ComboBox widgets that manipulate widget state in a way that frees the underlying object, then re-accesses it. See the Talos Intelligence Vulnerability Report for technical details.
Detection Methods for CVE-2024-25648
Indicators of Compromise
- PDF files containing JavaScript actions that manipulate ComboBox widgets in unusual sequences (rapid creation, modification, and deletion).
- Foxit Reader processes (FoxitPDFReader.exe, FoxitPDFEditor.exe) spawning child processes such as cmd.exe, powershell.exe, or unsigned binaries.
- Unexpected crashes or access violations in Foxit Reader correlated with PDF document opens.
- Outbound network connections initiated by Foxit Reader to non-Foxit infrastructure shortly after a document is opened.
Detection Strategies
- Inspect PDF attachments at the email gateway for embedded JavaScript referencing ComboBox field actions.
- Apply YARA rules that flag PDFs containing /JS, /JavaScript, and ComboBox widget annotations in suspicious combinations.
- Monitor endpoint telemetry for Foxit Reader memory access violations and exception events.
- Correlate browser-to-PDF-reader process chains when the Foxit browser plugin is enabled.
Monitoring Recommendations
- Enable process creation logging (Sysmon Event ID 1) and audit all child processes of Foxit Reader binaries.
- Capture image load events for Foxit Reader to identify unsigned or unexpected DLLs.
- Forward PDF reader crash dumps and Windows Error Reporting events to a central SIEM for triage.
- Track outbound network connections originating from Foxit Reader to detect post-exploitation command-and-control activity.
How to Mitigate CVE-2024-25648
Immediate Actions Required
- Upgrade Foxit PDF Reader and Foxit PDF Editor to the latest fixed release published by Foxit after version 2024.1.0.63682.
- Disable the Foxit browser plugin extension in all supported browsers until patching completes.
- Block inbound PDF attachments from untrusted senders at the email gateway during the remediation window.
- Enforce least-privilege execution so Foxit Reader runs without administrative rights.
Patch Information
Foxit addresses the use-after-free in builds released after 2024.1.0.63682. Administrators should consult the Talos Intelligence Vulnerability Report and Foxit's official security bulletins for the specific fixed build number, then deploy the update through standard software distribution channels across Windows and macOS endpoints.
Workarounds
- Disable JavaScript execution in Foxit Reader under Preferences → JavaScript → Enable JavaScript Actions.
- Uninstall or disable the Foxit browser plugin to eliminate the drive-by exploitation path.
- Open untrusted PDF files only in a sandboxed environment or alternate viewer until patches are applied.
- Apply application allowlisting to prevent Foxit Reader from spawning interpreters such as powershell.exe or cmd.exe.
# Disable Foxit Reader JavaScript via registry on Windows
reg add "HKCU\Software\Foxit Software\Foxit PDF Reader\Preferences\JavaScript" /v bEnableJS /t REG_DWORD /d 0 /f
# Verify the setting
reg query "HKCU\Software\Foxit Software\Foxit PDF Reader\Preferences\JavaScript" /v bEnableJS
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
