CVE-2016-3074 in GD Library
Summary
by MITRE
Integer signedness error in GD Graphics Library 2.1.1 (aka libgd or libgd2) allows remote attackers to cause a denial of service (crash) or potentially execute arbitrary code via crafted compressed gd2 data, which triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 12/01/2024
The vulnerability identified as CVE-2016-3074 represents a critical integer signedness error within the GD Graphics Library version 2.1.1, commonly known as libgd or libgd2. This flaw exists in the library's handling of compressed gd2 image data, which is widely used for image processing in web applications and server environments. The issue stems from improper validation of integer values during the decompression process, creating a scenario where maliciously crafted input can trigger unexpected behavior in the software's memory management systems.
The technical implementation of this vulnerability involves a heap-based buffer overflow that occurs when the library processes malformed compressed gd2 data. During the decompression routine, the library fails to properly validate the signedness of integer values used to determine buffer sizes and memory allocation limits. This oversight allows attackers to manipulate the decompression process by providing carefully constructed data that causes integer overflow conditions. When these overflow conditions occur, they result in memory corruption that can manifest as either a denial of service through application crashes or more severe exploitation leading to arbitrary code execution.
The operational impact of CVE-2016-3074 extends across numerous systems that rely on the GD Graphics Library for image processing tasks. Web servers running applications such as PHP, Perl, and other scripting languages that utilize libgd for image manipulation are particularly vulnerable. The vulnerability affects not only direct web application usage but also any system that processes user-uploaded image files or generates dynamic images through the library. Attackers can exploit this flaw by uploading malicious image files or by crafting requests that trigger the vulnerable decompression routine, potentially leading to complete system compromise.
This vulnerability maps to CWE-190, which specifically addresses integer overflow and underflow conditions, and aligns with ATT&CK technique T1203, representing Exploitation for Client Execution, as it enables remote code execution through image processing. The flaw also relates to T1499, which covers Network Denial of Service attacks, as the vulnerability can be leveraged to crash services. Organizations using vulnerable versions of libgd should implement immediate mitigations including updating to patched versions, implementing input validation for image files, and deploying network segmentation controls. The recommended remediation involves upgrading to GD Graphics Library version 2.1.2 or later, which includes proper integer validation and bounds checking to prevent the signedness error from causing memory corruption. Additionally, deploying web application firewalls and implementing strict file type validation can provide additional layers of protection against exploitation attempts targeting this vulnerability.