CVE-2021-29367 in Irfanview
Summary
by MITRE • 09/28/2021
A buffer overflow vulnerability in WPG+0x1dda of Irfanview 4.57 allows attackers to execute arbitrary code via a crafted WPG file.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/06/2026
The buffer overflow vulnerability identified as CVE-2021-29367 resides within the IrfanView image viewer version 4.57 specifically affecting the WPG+0x1dda component. This flaw represents a critical security issue that enables remote code execution through maliciously crafted WPG image files. The vulnerability stems from inadequate input validation and memory management within the application's handling of WPG file formats, which are proprietary graphics formats used by IrfanView for various image processing operations. The flaw manifests when the application attempts to parse and render specially constructed WPG files without proper bounds checking, leading to memory corruption that can be exploited by attackers to gain unauthorized system access.
This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The technical implementation involves the application's failure to properly validate the size of data structures within WPG files before attempting to copy or process this data into fixed-size buffers. When an attacker crafts a malicious WPG file containing oversized data structures or malformed headers, the vulnerable code path executes and overflows the allocated buffer space, potentially allowing arbitrary code execution with the privileges of the affected user. The attack vector is particularly concerning because it requires no user interaction beyond opening the malicious file, making it an ideal candidate for phishing campaigns or automated exploitation.
The operational impact of CVE-2021-29367 extends beyond simple code execution to encompass complete system compromise and potential lateral movement within network environments. Attackers exploiting this vulnerability can gain unauthorized access to systems running vulnerable IrfanView versions, potentially leading to data exfiltration, persistence mechanisms, or use as a stepping stone for broader network infiltration. The vulnerability affects Windows operating systems where IrfanView is installed, with the attack surface expanding to any user who might encounter or open malicious WPG files through the application. Organizations using IrfanView for image processing or document management are particularly at risk, as the application's widespread use across various industries creates multiple potential attack vectors.
Mitigation strategies for CVE-2021-29367 should prioritize immediate patching of affected IrfanView installations to version 4.58 or later, which contains the necessary security fixes. System administrators should implement network-based restrictions to prevent the execution of potentially malicious WPG files through email attachments, web downloads, or file transfers. The principle of least privilege should be enforced by running IrfanView with minimal user permissions and avoiding execution of the application with administrator privileges. Additionally, organizations should consider implementing application whitelisting policies that restrict execution of unauthorized applications, including IrfanView, unless explicitly permitted. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1059.007 for command and script interpreter and T1203 for Exploitation for Client Execution, making it a critical target for defensive measures and threat hunting activities. Regular security assessments should include scanning for vulnerable IrfanView installations and monitoring for suspicious file execution patterns that may indicate exploitation attempts.