CVE-2006-4811 in Digia
Summary
by MITRE
Integer overflow in Qt 3.3 before 3.3.7, 4.1 before 4.1.5, and 4.2 before 4.2.1, as used in the KDE khtml library, kdelibs 3.1.3, and possibly other packages, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted pixmap image.
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Analysis
by VulDB Data Team • 04/24/2026
The vulnerability described in CVE-2006-4811 represents a critical integer overflow flaw affecting Qt libraries version 3.3 prior to 3.3.7, 4.1 prior to 4.1.5, and 4.2 prior to 4.2.1. This issue specifically impacts the KDE khtml library and kdelibs 3.1.3, creating a significant security risk that extends beyond these specific components to potentially affect other packages utilizing the affected Qt versions. The flaw resides in how the software handles pixmap image processing, where improper integer handling during image parsing creates exploitable conditions that can be leveraged by remote attackers.
The technical nature of this vulnerability stems from an integer overflow condition that occurs when processing crafted pixmap images. When the Qt library attempts to parse maliciously constructed image files, the integer arithmetic operations exceed the maximum representable value for the data type being used, causing unexpected behavior in the application's memory management and control flow. This overflow condition can lead to memory corruption, which manifests as application crashes or, in more sophisticated exploitation scenarios, allows for arbitrary code execution within the context of the affected application. The vulnerability operates at the boundary between valid and invalid image data processing, where the software fails to properly validate input parameters before performing arithmetic operations that could result in overflow conditions.
The operational impact of this vulnerability is substantial, as it enables remote attackers to trigger denial of service conditions through simple crafted image files that could crash applications using the affected Qt libraries. Beyond the immediate denial of service capability, the integer overflow presents potential for more severe exploitation where attackers could leverage the memory corruption to execute arbitrary code, potentially gaining unauthorized access to systems running vulnerable software. The widespread use of Qt libraries in desktop applications and web browsers means that this vulnerability could affect numerous applications across different platforms, creating a broad attack surface that extends from desktop environments to web-based applications that utilize Qt components for rendering functionality.
Mitigation strategies for this vulnerability involve immediate patching of affected Qt library versions to the secure releases that address the integer overflow conditions. System administrators should prioritize updating all instances of Qt 3.3, 4.1, and 4.2 libraries to their respective patched versions, particularly focusing on systems running KDE khtml library and kdelibs 3.1.3 components. Additionally, implementing input validation measures and image sanitization protocols can provide defensive layers against exploitation attempts, though these approaches are secondary to the primary requirement of applying official patches. Organizations should also consider monitoring for exploitation attempts through network traffic analysis and application logs to detect potential attacks targeting this specific vulnerability.
This vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions, and represents a classic example of how improper input validation and arithmetic operation handling can create security weaknesses. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and code execution through software exploitation, specifically targeting the application layer where memory corruption occurs. The vulnerability demonstrates the importance of secure coding practices, particularly in handling integer arithmetic and input validation, as outlined in various secure coding standards and best practices that emphasize the need for comprehensive bounds checking and proper error handling in all arithmetic operations involving user-supplied data.