CVE-2020-27752 in ImageMagick
Summary
by MITRE • 12/09/2020
A flaw was found in ImageMagick in MagickCore/quantum-private.h. An attacker who submits a crafted file that is processed by ImageMagick could trigger a heap buffer overflow. This would most likely lead to an impact to application availability, but could potentially lead to an impact to data integrity as well. This flaw affects ImageMagick versions prior to 7.0.9-0.
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Analysis
by VulDB Data Team • 12/14/2020
The vulnerability identified as CVE-2020-27752 represents a critical heap buffer overflow condition within ImageMagick's MagickCore component, specifically in the quantum-private.h header file. This flaw exists in the processing pipeline where ImageMagick handles various image formats, creating a potential attack surface for malicious actors who can craft specially formatted files designed to exploit this memory corruption issue. The vulnerability stems from inadequate bounds checking during the handling of image data structures, particularly when processing quantum values that represent pixel color information in the image processing pipeline. The flaw affects all ImageMagick versions prior to the 7.0.9-0 release, indicating that this was a long-standing issue that required significant codebase modifications to address properly. The vulnerability is particularly concerning because it can be triggered through normal file processing operations, making it accessible to attackers who might upload malicious files to systems running vulnerable ImageMagick versions.
The technical exploitation of this vulnerability occurs when an attacker submits a crafted image file that, upon processing by ImageMagick, causes the application to write beyond the allocated heap memory boundaries. This heap buffer overflow can result in memory corruption that may manifest as application crashes, denial of service conditions, or potentially more severe impacts including arbitrary code execution depending on the execution environment and memory layout. The vulnerability's impact extends beyond simple availability issues as the buffer overflow can corrupt adjacent memory regions, potentially affecting data integrity by modifying critical application state or user data. The flaw specifically affects the quantum handling mechanisms within MagickCore, which are responsible for managing the bit depth and color representation of image data during processing operations. This makes it particularly dangerous in environments where ImageMagick is used for image conversion, manipulation, or automated processing tasks where untrusted input is commonly processed.
The operational impact of CVE-2020-27752 is significant across multiple deployment scenarios where ImageMagick is utilized for image processing tasks. Systems that accept user-uploaded images, such as web applications, content management systems, and media processing platforms, are particularly vulnerable to this attack vector. The vulnerability can be exploited through various image formats that ImageMagick supports, making it difficult to completely mitigate by simply blocking specific file types. The flaw's potential for causing application instability means that systems running vulnerable versions could experience unexpected service interruptions, data loss, or in severe cases, complete system compromise if the overflow leads to code execution. Organizations using ImageMagick in automated processing pipelines face additional risk as the vulnerability can be triggered during routine operations without manual intervention from users. This makes the vulnerability particularly dangerous in production environments where continuous processing occurs and where the impact of a single malicious file could affect large volumes of legitimate processing operations.
Mitigation strategies for CVE-2020-27752 focus primarily on upgrading to ImageMagick version 7.0.9-0 or later, which includes the necessary patches to address the heap buffer overflow condition. Organizations should implement comprehensive patch management procedures to ensure all systems running ImageMagick are updated promptly. Additionally, deploying input validation and sanitization measures can provide additional defense in depth, including restricting image file types, implementing size limits, and using sandboxed processing environments. The vulnerability aligns with CWE-121, heap-based buffer overflow, and can be mapped to ATT&CK technique T1203, Exploitation for Client Execution, when exploited in web application contexts. System administrators should also consider implementing network-based intrusion detection systems to monitor for exploitation attempts and establish monitoring procedures to detect abnormal processing behavior that might indicate successful exploitation. Organizations should conduct thorough vulnerability assessments to identify all systems running vulnerable ImageMagick versions and prioritize remediation efforts based on risk exposure and system criticality. The fix implemented in version 7.0.9-0 specifically addresses the memory allocation and bounds checking mechanisms within the quantum processing code, ensuring that all buffer operations are properly validated before memory access occurs.