CVE-2017-12435 in ImageMagick
Summary
by MITRE
In ImageMagick 7.0.6-1, a memory exhaustion vulnerability was found in the function ReadSUNImage in coders/sun.c, which allows attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 12/14/2022
The vulnerability identified as CVE-2017-12435 represents a critical memory exhaustion flaw within ImageMagick's SUN image format processing functionality. This issue manifests in the ReadSUNImage function located within the coders/sun.c source file of ImageMagick version 7.0.6-1, where improper memory management during image parsing creates an avenue for malicious exploitation. The vulnerability specifically targets the memory allocation mechanisms used when processing SUN format image files, which are commonly used in unix systems for storing raster graphics data. Attackers can craft specially malformed SUN image files that trigger excessive memory consumption during the parsing process, leading to system resource exhaustion and subsequent denial of service conditions.
The technical root cause of this vulnerability stems from inadequate bounds checking and memory allocation validation within the image parsing pipeline. When ImageMagick attempts to read a SUN image file, the ReadSUNImage function fails to properly validate the size parameters embedded within the image header structure. This allows attackers to specify arbitrarily large dimensions or memory requirements that the system cannot accommodate, resulting in memory allocation failures or system instability. The flaw operates at the intersection of buffer overflow conditions and resource exhaustion attacks, where the malicious input causes the application to allocate excessive memory blocks that can overwhelm system resources or trigger memory allocation failures. This vulnerability aligns with CWE-122 which describes insufficient memory allocation validation and CWE-400 which covers uncontrolled resource consumption.
From an operational perspective, this vulnerability presents a significant risk to systems that process untrusted image content, particularly web applications, file processing services, and content management systems that utilize ImageMagick for image handling. The denial of service impact can be severe as it can cause complete application unavailability, requiring system restarts and potentially leading to cascading failures in dependent services. The attack vector is particularly concerning because it requires minimal skill to exploit, as attackers only need to craft a malicious SUN image file to trigger the memory exhaustion condition. This makes the vulnerability attractive to threat actors seeking to disrupt services or conduct resource exhaustion attacks against systems processing image content.
Security mitigations for CVE-2017-12435 should prioritize immediate patching of ImageMagick installations to versions that address the memory allocation validation issues in the SUN image processing code. System administrators should implement strict file format validation and size limiting for all image processing operations, particularly in web-facing applications where untrusted user uploads are common. Network-based protections can include implementing content filtering rules that block or quarantine suspicious image files before they reach processing systems. The vulnerability demonstrates the importance of proper input validation and resource management in multimedia processing libraries, aligning with ATT&CK technique T1499.004 which covers network denial of service attacks. Organizations should also consider implementing monitoring and alerting for unusual memory consumption patterns that may indicate exploitation attempts, as the vulnerability creates predictable resource exhaustion behaviors that can be detected through system performance monitoring.