CVE-2024-6811 Overview
CVE-2024-6811 is an out-of-bounds write vulnerability [CWE-787] in IrfanView's WSQ file parsing logic. The flaw allows attackers to execute arbitrary code in the context of the current user by delivering a crafted WSQ image file. Exploitation requires user interaction: the victim must open a malicious file or visit a page that triggers the parser. The issue was reported through the Zero Day Initiative as ZDI-CAN-24192 and disclosed in advisory ZDI-24-903.
Critical Impact
Successful exploitation grants arbitrary code execution with the privileges of the IrfanView process, enabling full compromise of the local user context.
Affected Products
- IrfanView 4.67 (x86)
- IrfanView WSQ plugin 2024.02.16 (x64)
- Installations bundling the vulnerable WSQ image format handler
Discovery Timeline
- 2024-08-21 - CVE-2024-6811 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-6811
Vulnerability Analysis
The vulnerability resides in IrfanView's parser for Wavelet Scalar Quantization (WSQ) files, a format used primarily for compressed fingerprint imagery. The parser fails to validate user-supplied dimensions or length fields before writing decoded data into an allocated buffer. As a result, attacker-controlled bytes are written past the end of that buffer.
Out-of-bounds writes in native image parsers typically corrupt adjacent heap metadata, function pointers, or object vtables. An attacker who controls the overflow contents can pivot to arbitrary code execution within the IrfanView process. Because IrfanView runs in the user's session and often handles files received by email or download, this class of flaw is well suited to targeted phishing.
Root Cause
The root cause is missing bounds validation on values parsed from the WSQ header or compressed data stream. The WSQ handler trusts embedded length or dimension fields when computing write offsets, without confirming that the destination buffer accommodates the resulting write. This falls squarely within [CWE-787] Out-of-Bounds Write.
Attack Vector
Exploitation is local and requires user interaction. An attacker crafts a malicious .wsq file and delivers it through phishing, a drive-by download, or a malicious webpage that instructs the browser to hand the file to IrfanView. When the victim opens the file, the WSQ parser processes the malformed structure and triggers the out-of-bounds write. No verified public proof-of-concept code is available. Refer to the Zero Day Initiative Advisory ZDI-24-903 for technical details.
Detection Methods for CVE-2024-6811
Indicators of Compromise
- Unexpected .wsq files arriving via email attachments, shared drives, or browser downloads on hosts with IrfanView installed.
- Crashes or abnormal termination of i_view32.exe or i_view64.exe correlated with WSQ file access.
- Child processes spawned by IrfanView that are inconsistent with normal image-viewing workflows, such as command shells or script interpreters.
Detection Strategies
- Monitor endpoint telemetry for IrfanView processes loading the WSQ plugin and immediately spawning cmd.exe, powershell.exe, or rundll32.exe.
- Alert on heap-corruption exceptions and access-violation crashes originating from the IrfanView image module.
- Inspect email and web gateways for attachments with the WSQ extension or WSQ magic bytes, which are uncommon in typical enterprise traffic.
Monitoring Recommendations
- Enable process-creation and image-load logging on workstations with IrfanView deployed and forward events to a central analytics platform.
- Track file-open events for .wsq extensions and correlate with subsequent process behavior.
- Include IrfanView in software inventory scans to identify unpatched installations of version 4.67 and the WSQ plugin build 2024.02.16.
How to Mitigate CVE-2024-6811
Immediate Actions Required
- Inventory all endpoints running IrfanView 4.67 and the WSQ plugin, and prioritize them for update.
- Upgrade IrfanView and the WSQ plugin to the latest versions published by the vendor after the ZDI-24-903 disclosure.
- Restrict file-association handling so that .wsq files are not opened automatically by IrfanView on untrusted content.
Patch Information
Consult the vendor download page for updated IrfanView and WSQ plugin builds released after the disclosure. The Zero Day Initiative Advisory ZDI-24-903 tracks disclosure status and vendor remediation for this issue.
Workarounds
- Remove the WSQ plugin from IrfanView installations that do not require fingerprint image support.
- Block .wsq attachments at the email gateway and web proxy for user populations without a legitimate business need.
- Educate users to avoid opening WSQ files from untrusted sources until patched builds are deployed.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
