CVE-2018-3977 in SDL2_image
Summary
by MITRE
An exploitable code execution vulnerability exists in the XCF image rendering functionality of SDL2_image-2.0.3. A specially crafted XCF image can cause a heap overflow, resulting in code execution. An attacker can display a specially crafted image to trigger this vulnerability.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-3977 represents a critical heap overflow condition within the SDL2_image library version 2.0.3, specifically affecting the XCF image rendering component. This flaw resides in the library's handling of GIMP's native image format XCF files, which are commonly used for preserving image data with layers and other advanced features. The vulnerability stems from inadequate input validation and memory management when processing malformed XCF files, creating a pathway for malicious actors to execute arbitrary code on systems running affected software.
The technical implementation of this vulnerability involves a classic heap buffer overflow scenario where the SDL2_image library fails to properly bounds-check data during XCF file parsing. When the library encounters specially crafted XCF image data containing oversized or malformed elements, it attempts to allocate memory regions that exceed predetermined limits, leading to memory corruption. This heap overflow can be strategically manipulated to overwrite adjacent memory locations, potentially including function pointers, return addresses, or other critical control data structures. The flaw operates at the intersection of multiple security domains including memory safety, input validation, and software robustness, making it particularly dangerous in environments where image processing is common.
The operational impact of CVE-2018-3977 extends beyond simple code execution capabilities, as it can be leveraged in various attack scenarios including remote code execution in applications that utilize SDL2_image for image display. Systems vulnerable to this exploit include web browsers, media players, graphic design applications, and any software that incorporates SDL2_image for XCF file handling. The vulnerability's trigger mechanism is particularly concerning as it requires only the display of a malicious image file, making it suitable for phishing campaigns, malicious websites, or social engineering attacks where users might unknowingly interact with compromised content. This makes the vulnerability particularly attractive to threat actors seeking to exploit user trust in image viewing applications.
Mitigation strategies for CVE-2018-3977 primarily involve immediate software updates to SDL2_image version 2.0.4 or later, which contains patches addressing the heap overflow condition through improved bounds checking and memory allocation routines. Security-conscious organizations should also implement defensive measures such as restricting image file type handling in applications, implementing sandboxing for image processing components, and deploying network-based intrusion detection systems to monitor for exploitation attempts. From a compliance perspective, this vulnerability aligns with CWE-121, heap-based buffer overflow, and maps to ATT&CK technique T1059.007 for command and scripting interpreter usage, demonstrating how the vulnerability could be exploited to establish persistent access. Additionally, organizations should consider implementing application whitelisting policies that restrict execution of untrusted image files, particularly in high-risk environments where sensitive data processing occurs.