CVE-2019-7637 in Simple DirectMedia Layer
Summary
by MITRE
SDL (Simple DirectMedia Layer) through 1.2.15 and 2.x through 2.0.9 has a heap-based buffer overflow in SDL_FillRect in video/SDL_surface.c.
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Analysis
by VulDB Data Team • 07/09/2023
The vulnerability identified as CVE-2019-7637 represents a critical heap-based buffer overflow within the Simple DirectMedia Layer library, affecting versions through 1.2.15 and 2.x through 2.0.9. This flaw exists within the SDL_FillRect function located in the video/SDL_surface.c source file, making it a fundamental component of the multimedia framework's rendering capabilities. The vulnerability stems from inadequate bounds checking when processing rectangle fill operations, creating a condition where malicious input can cause memory corruption beyond the allocated buffer boundaries.
The technical implementation of this vulnerability involves the SDL_FillRect function failing to properly validate input parameters before performing memory operations on surface buffers. When applications invoke this function with malformed rectangle coordinates or dimensions, the underlying memory allocation and copying mechanisms can overwrite adjacent heap memory regions. This buffer overflow condition allows attackers to potentially execute arbitrary code or cause application crashes through controlled memory corruption. The vulnerability specifically manifests when the function processes rectangle dimensions that exceed the allocated buffer size, creating a classic heap overflow scenario that aligns with CWE-121 heap-based buffer overflow classification.
From an operational impact perspective, this vulnerability affects a wide range of applications that utilize the SDL library for multimedia operations including games, media players, and graphics-intensive software. The exploitability of this flaw increases significantly when applications process untrusted input through SDL surface operations, as attackers can craft malicious rectangle parameters that trigger the overflow condition. The vulnerability's severity is amplified by the widespread adoption of SDL across multiple platforms and development environments, potentially affecting thousands of applications. Security researchers have noted that exploitation of this vulnerability can lead to complete system compromise when applications are running with elevated privileges, making it particularly dangerous in enterprise environments.
Mitigation strategies for CVE-2019-7637 primarily involve immediate application updates to SDL versions that have patched the buffer overflow issue, specifically SDL 1.2.16 and SDL 2.0.10 or later. Organizations should implement comprehensive code review processes to identify and remediate any custom implementations that may be vulnerable, particularly focusing on input validation within graphics rendering functions. The ATT&CK framework categorizes this vulnerability under T1059 command and scripting interpreter execution, as exploitation may involve crafting malicious input that triggers the overflow. Additionally, memory safety improvements such as address space layout randomization and stack canaries should be implemented to reduce exploit reliability, while regular security updates and dependency management practices help prevent similar vulnerabilities in future software releases.