CVE-2024-11540 Overview
CVE-2024-11540 is an out-of-bounds read vulnerability [CWE-125] in IrfanView, a widely deployed Windows image viewer. The flaw resides in the parser that handles Drawing Exchange Format (DXF) files. Attackers can leverage the issue to execute arbitrary code in the context of the current user. Exploitation requires user interaction, such as opening a crafted DXF file or visiting a malicious page that delivers one. The Zero Day Initiative tracks the issue as ZDI-CAN-24700 and published advisory ZDI-24-1551.
Critical Impact
A crafted DXF file can trigger memory disclosure and arbitrary code execution in the context of the IrfanView process on affected Windows systems.
Affected Products
- IrfanView 4.67 (x64)
- IrfanView 4.67 (x86)
- Systems where IrfanView is registered as a DXF file handler
Discovery Timeline
- 2024-11-22 - CVE-2024-11540 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-11540
Vulnerability Analysis
The vulnerability exists in IrfanView's DXF file parser. DXF is an ASCII or binary CAD interchange format that stores drawing entities using tagged group codes and length-prefixed sections. The parser fails to validate user-supplied length or index values before reading from heap-allocated buffers. When IrfanView opens a crafted DXF file, the parser reads past the end of an allocated buffer, exposing adjacent memory to attacker-controlled logic. An attacker can chain this primitive with information disclosure of pointers and object metadata to bypass Address Space Layout Randomization (ASLR) and pivot into arbitrary code execution within the IrfanView process.
Root Cause
The root cause is missing bounds validation on user-controlled fields inside DXF records. The parser trusts size or offset values embedded in the file and dereferences the resulting pointer without verifying it against the allocation boundary. This maps to CWE-125: Out-of-bounds Read as classified by the National Vulnerability Database (NVD).
Attack Vector
Exploitation is local and requires user interaction. A target must open a malicious DXF file, either from disk, an email attachment, or a link that delivers the file through the browser. Because IrfanView commonly registers itself as the default handler for many image and CAD-adjacent formats, a double-click on an attachment can be sufficient. The vulnerability yields code execution with the privileges of the current user, which typically supports follow-on credential theft, persistence, or lateral movement.
No verified exploitation code is publicly available. See the Zero Day Initiative Advisory ZDI-24-1551 for the coordinated technical writeup.
Detection Methods for CVE-2024-11540
Indicators of Compromise
- Unexpected i_view32.exe or i_view64.exe process crashes with access violation events referencing DXF files.
- DXF files delivered through email or web downloads that are opened by IrfanView outside of normal CAD workflows.
- Child processes such as cmd.exe, powershell.exe, or rundll32.exe spawned by IrfanView after opening a document.
Detection Strategies
- Alert on IrfanView loading files with the .dxf extension in environments where DXF handling is not expected.
- Monitor for anomalous outbound network connections initiated by the IrfanView process shortly after file open events.
- Correlate Windows Error Reporting (WER) crash dumps involving IrfanView with recent email or browser download telemetry.
Monitoring Recommendations
- Ingest Sysmon Event ID 1 (process creation) and Event ID 11 (file create) to track DXF file drops and IrfanView launches.
- Track image loads and memory allocation anomalies in IrfanView using EDR telemetry.
- Baseline the population of hosts running IrfanView 4.67 to scope patch and detection coverage.
How to Mitigate CVE-2024-11540
Immediate Actions Required
- Inventory all endpoints running IrfanView 4.67 (x86 and x64) and prioritize workstations that process external files.
- Upgrade to a fixed IrfanView release as referenced in ZDI-24-1551.
- Remove IrfanView as the default handler for .dxf files until patched, using file association policies.
- Block inbound DXF attachments at the email gateway where CAD file exchange is not a business requirement.
Patch Information
The vendor has coordinated disclosure through the Zero Day Initiative under advisory ZDI-24-1551. Administrators should install the latest IrfanView release from the vendor and validate that the patched build no longer parses malformed DXF samples without triggering the out-of-bounds read. No vendor-hosted advisory URL is listed in the NVD entry beyond the ZDI reference.
Workarounds
- Disassociate the .dxf extension from IrfanView using the Windows Default Apps settings or Group Policy.
- Restrict IrfanView execution through application control policies such as Windows Defender Application Control (WDAC) or AppLocker on high-risk hosts.
- Enforce Attack Surface Reduction (ASR) rules that block child process creation from Office and mail clients to limit downstream execution.
# Configuration example: remove the .dxf handler for IrfanView via PowerShell
Remove-Item -Path "HKCU:\Software\Classes\.dxf" -Recurse -ErrorAction SilentlyContinue
Remove-Item -Path "HKCU:\Software\Classes\IrfanView.DXF" -Recurse -ErrorAction SilentlyContinue
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
