CVE-2019-19953 in GraphicsMagick
Summary
by MITRE
In GraphicsMagick 1.4 snapshot-20191208 Q8, there is a heap-based buffer over-read in the function EncodeImage of coders/pict.c.
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Analysis
by VulDB Data Team • 03/16/2024
The vulnerability CVE-2019-19953 represents a critical heap-based buffer over-read flaw within GraphicsMagick's image processing library, specifically affecting version 1.4 snapshot-20191208 Q8. This issue occurs within the EncodeImage function located in the coders/pict.c source file, which handles the encoding of image data for the pict format. The flaw arises when the software attempts to read memory beyond the allocated buffer boundaries during the image encoding process, potentially exposing sensitive data or causing application instability. Such vulnerabilities are particularly dangerous in image processing libraries that handle untrusted input from various sources, as they can be exploited to extract confidential information from memory or cause denial of service conditions.
The technical implementation of this vulnerability stems from inadequate bounds checking within the EncodeImage function, which fails to properly validate the size of data being processed against the allocated buffer space. When processing certain pict format image files, the function reads beyond the intended memory boundaries, potentially accessing adjacent memory regions that may contain sensitive information such as stack canaries, return addresses, or other process data. This type of flaw falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions in software implementations. The vulnerability can be triggered through maliciously crafted pict image files that exploit the insufficient input validation mechanisms in the encoding process.
From an operational perspective, this vulnerability poses significant risks to systems that utilize GraphicsMagick for image processing tasks, particularly in web applications, content management systems, or any environment where users can upload image files. Attackers could leverage this flaw to perform information disclosure attacks, potentially extracting sensitive data from the application's memory space, or to cause application crashes leading to denial of service conditions. The impact extends beyond simple memory corruption, as the over-read could expose cryptographic keys, session tokens, or other confidential information stored in adjacent memory locations. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage, as attackers might exploit it to gain additional system information or escalate privileges through memory exposure.
Mitigation strategies for CVE-2019-19953 should prioritize immediate patching of affected GraphicsMagick installations to the latest stable version that contains the necessary buffer validation fixes. Organizations should implement comprehensive input validation measures that restrict image file uploads to known good formats and sizes, while also deploying runtime protections such as address space layout randomization and stack canaries. Additionally, network segmentation and access controls should be enforced to limit the potential impact of exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other image processing libraries and dependencies. The fix typically involves implementing proper bounds checking mechanisms within the EncodeImage function to ensure that all memory reads remain within allocated buffer boundaries, preventing the over-read condition that enables the vulnerability exploitation.