CVE-2020-23897 in Viewer
Summary
by MITRE • 11/11/2021
A User Mode Write AV in Editor!TMethodImplementationIntercept+0x54dcec of WildBit Viewer v6.6 allows attackers to cause a denial of service (DoS) via a crafted tga file.
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Analysis
by VulDB Data Team • 11/12/2021
The vulnerability identified as CVE-2020-23897 represents a critical user mode write access violation within WildBit Viewer version 6.6 that manifests during the processing of specially crafted tga image files. This issue occurs within the Editor!TMethodImplementationIntercept+0x54dcec function, indicating a flaw in how the application handles method interception during image processing operations. The vulnerability stems from insufficient input validation and memory management when parsing tga file formats, creating an opportunity for attackers to exploit memory corruption patterns that can lead to application instability.
The technical exploitation of this vulnerability involves crafting a malicious tga file that triggers an invalid write operation within the application's memory space. When WildBit Viewer attempts to process such a file, the tga parser fails to properly validate the file structure and metadata, leading to a write access violation at the specific memory location referenced in the function offset. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow conditions, though it manifests as a write access violation rather than traditional buffer overflow. The flaw essentially allows an attacker to write data to memory locations that should be protected or read-only, creating potential for arbitrary code execution or system instability.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially enable more sophisticated attacks within the context of the application's execution environment. When an attacker successfully triggers this write access violation, the application crashes or becomes unresponsive, effectively causing a denial of service condition that prevents legitimate users from accessing the viewer functionality. However, the underlying memory corruption could theoretically be leveraged to execute arbitrary code if proper exploit mitigations are not in place, making this a potentially serious security concern for systems where the viewer is used to process untrusted image files.
Mitigation strategies for CVE-2020-23897 should focus on immediate patching of the affected WildBit Viewer version 6.6, as well as implementing defensive programming practices such as input validation and memory bounds checking. Organizations should consider deploying application whitelisting controls to restrict execution of potentially vulnerable applications and implement sandboxing mechanisms to contain potential exploitation attempts. The vulnerability demonstrates the importance of proper input sanitization and memory management in image processing libraries, aligning with ATT&CK technique T1059.007 for process injection and T1203 for exploitation for client execution. System administrators should monitor for suspicious file processing activities and implement network-based intrusion detection systems to identify potential exploitation attempts targeting this specific vulnerability pattern. Additionally, regular security assessments of image processing components and adherence to secure coding practices including the use of modern memory safety features and static analysis tools can significantly reduce the risk of similar vulnerabilities in future implementations.