CVE-2018-7589 in CImg
Summary
by MITRE
An issue was discovered in CImg v.220. A double free in load_bmp in CImg.h occurs when loading a crafted bmp image.
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Analysis
by VulDB Data Team • 02/16/2023
The vulnerability identified as CVE-2018-7589 represents a critical memory corruption flaw within the CImg library version 220, specifically manifesting as a double free condition during the processing of maliciously crafted bmp image files. This issue resides within the load_bmp function of the CImg.h header file, which serves as a core component in the CImg image processing library widely utilized in various software applications for computer graphics and image manipulation tasks. The double free vulnerability occurs when the library attempts to release the same memory block twice, creating an exploitable condition that can lead to arbitrary code execution or denial of service scenarios.
The technical implementation of this vulnerability stems from improper memory management within the image loading routine. When processing a specially crafted bmp file, the load_bmp function fails to properly track memory allocations and deallocations, resulting in a scenario where a memory pointer is freed twice during the execution flow. This flaw directly maps to CWE-415, which describes improper double free conditions in software applications, and aligns with ATT&CK technique T1059.007 for execution through command and scripting interpreter. The vulnerability exploitation typically involves crafting a malicious bmp file that triggers the double free condition during image parsing, potentially allowing attackers to manipulate heap memory structures and execute arbitrary code with the privileges of the affected application.
The operational impact of CVE-2018-7589 extends beyond simple denial of service to encompass potential remote code execution capabilities, making it particularly dangerous in environments where applications process untrusted image files from external sources. Software applications that integrate CImg library for image handling, including multimedia applications, image editors, and content management systems, become vulnerable to this exploit. The vulnerability is especially concerning in web applications that accept user-uploaded images or process images from remote sources, as attackers can craft malicious bmp files to compromise these systems. The double free condition creates opportunities for heap spraying, memory corruption, and potential privilege escalation depending on the execution environment and target application.
Mitigation strategies for this vulnerability involve immediate application of patches or updates to CImg library versions that address the double free condition in load_bmp function. System administrators should implement input validation and sanitization measures to prevent processing of untrusted image files, particularly those from external sources. Network security controls such as web application firewalls can be configured to block suspicious image file uploads or implement strict file type validation. The remediation process should include comprehensive code review of all applications utilizing CImg library to ensure proper memory management practices are implemented. Additionally, organizations should consider implementing memory safety features such as address space layout randomization and stack canaries to reduce exploitability. Regular security assessments and vulnerability scanning should be conducted to identify any other potential memory corruption issues within image processing components, with particular attention to similar double free patterns that may exist in other third-party libraries.