CVE-2017-8785 in Image Viewer
Summary
by MITRE
FastStone Image Viewer 6.2 has a "Data from Faulting Address may be used as a return value" issue. This issue can be triggered by a malformed JPEG 2000 file that is mishandled by FSViewer.exe. Attackers could exploit this issue for DoS (Access Violation) or possibly unspecified other impact.
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Analysis
by VulDB Data Team • 10/22/2019
The vulnerability identified as CVE-2017-8785 affects FastStone Image Viewer version 6.2 and represents a critical memory corruption flaw that arises from improper handling of malformed JPEG 2000 image files. This issue manifests within the FSViewer.exe executable when processing specially crafted input data that causes the application to read from an invalid memory address, potentially leading to unpredictable behavior and system instability. The vulnerability stems from a fundamental flaw in the image parsing logic where the software fails to properly validate and sanitize input data before attempting to use it as a return value in memory operations. Such improper handling of faulting addresses creates a dangerous condition where the application's execution flow becomes compromised, opening pathways for potential exploitation.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions that occur when a program attempts to read memory beyond the boundaries of a buffer or data structure. The flaw specifically manifests as a heap-based buffer overflow or memory corruption scenario where the application's internal data structures become corrupted during JPEG 2000 file processing. When the malformed file is loaded, the image viewer's parser encounters unexpected data patterns that cause it to dereference invalid memory addresses, resulting in access violations that typically crash the application. This behavior demonstrates characteristics consistent with memory safety issues that can be leveraged for more sophisticated attacks beyond simple denial of service.
The operational impact of this vulnerability extends beyond simple application crashes, as it presents a potential vector for more serious security incidents within the target system. While the primary reported consequence is access violation leading to denial of service, the nature of the memory corruption suggests that attackers might potentially exploit this weakness to execute arbitrary code or manipulate system behavior. The vulnerability affects a widely used image viewing application, making it particularly attractive to threat actors who could leverage it in targeted attacks or as part of broader exploitation campaigns. The fact that the issue occurs during image file processing means that it could be triggered through various attack vectors including email attachments, web downloads, or file sharing scenarios, making it a significant concern for enterprise security.
Mitigation strategies for CVE-2017-8785 should focus on immediate patching of the affected FastStone Image Viewer application to the latest version that contains the necessary memory validation fixes. System administrators should implement strict file validation policies that prevent execution of potentially malicious image files, particularly those from untrusted sources. Network-level controls such as content filtering and sandboxing mechanisms can help reduce the attack surface by isolating image processing operations from critical system components. The vulnerability also highlights the importance of input validation and memory safety practices in software development, aligning with ATT&CK technique T1203 for legitimate program execution and T1059 for command and scripting interpreter usage that attackers might employ to exploit similar weaknesses. Organizations should consider implementing application whitelisting policies that restrict execution of vulnerable software versions and ensure comprehensive testing of image processing capabilities in security monitoring systems.