CVE-2020-23901 in Viewer
Summary
by MITRE • 11/11/2021
A User Mode Write AV in Editor+0x5d15 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 • 11/16/2021
The vulnerability identified as CVE-2020-23901 represents a user mode write access violation within the WildBit Viewer v6.6 application, specifically occurring at offset 0x5d15 in the Editor+0x5d15 component. This flaw manifests when the application processes a specially crafted tga file format, creating a potential denial of service condition that can be exploited by remote attackers. The issue stems from inadequate input validation and memory management within the image processing pipeline of the viewer software, where the application fails to properly handle malformed tga file structures that could lead to unexpected memory access patterns.
This vulnerability operates at the application layer and falls under the category of memory corruption issues, specifically aligning with CWE-121 which describes stack-based buffer overflow conditions. The technical implementation involves the application's failure to validate the bounds of memory allocations when processing tga file headers and pixel data. When an attacker supplies a maliciously constructed tga file, the viewer attempts to write data beyond allocated memory boundaries, causing an access violation that terminates the application process. The flaw is particularly concerning as it can be triggered through simple file manipulation without requiring any special privileges or complex attack vectors.
The operational impact of this vulnerability extends beyond simple denial of service, as it can be leveraged to disrupt legitimate user workflows and potentially provide a foothold for more sophisticated attacks. Attackers can craft tga files that, when opened by the vulnerable viewer, will cause the application to crash repeatedly, effectively rendering the software unusable for its intended purpose. This type of vulnerability can be particularly damaging in enterprise environments where the viewer might be used for document review, image processing, or collaborative work scenarios. The vulnerability also demonstrates poor defensive programming practices and highlights the importance of implementing robust input sanitization and memory boundary checking mechanisms.
Mitigation strategies for CVE-2020-23901 should include immediate patching of the WildBit Viewer application to the latest version that addresses this specific memory corruption issue. Organizations should implement file validation procedures that scan for potentially malicious file formats before processing, particularly in environments where users may encounter untrusted content. Network-based protections such as content filtering systems can help prevent the delivery of malicious tga files through email attachments or web downloads. Additionally, users should be educated about the risks of opening files from untrusted sources and the importance of maintaining up-to-date software versions. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1203 (Exploitation for Execution) and T1499 (Endpoint Termination) where adversaries can leverage application flaws to cause system disruption and potentially establish persistent access through repeated exploitation attempts.