CVE-2017-10766 in XnView Classic
Summary
by MITRE
XnView Classic for Windows Version 2.40 might allow attackers to cause a denial of service or possibly have unspecified other impact via a crafted .rle file, related to "Data from Faulting Address controls Branch Selection starting at GDI32!ScriptStringAnalyse+0x00000000000001c8."
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Analysis
by VulDB Data Team • 10/22/2019
The vulnerability identified as CVE-2017-10766 affects XnView Classic for Windows version 2.40 and represents a critical denial of service flaw that could potentially lead to more severe consequences. This issue manifests through the processing of maliciously crafted .rle files, which are Run-Length Encoded image format files commonly used for compressing bitmap images. The vulnerability specifically targets the GDI32.dll component, which is a fundamental Windows graphics device interface library responsible for rendering graphical elements and managing display operations. When XnView Classic attempts to process an attacker-controlled .rle file, the application fails to properly validate the file structure, leading to unpredictable behavior in the underlying graphics subsystem.
The technical flaw stems from improper input validation within the image parsing routine that handles .rle file formats. The vulnerability occurs at the GDI32!ScriptStringAnalyse+0x00000000000001c8 memory address, indicating that the fault originates from the Windows Graphics Device Interface library's text string analysis function. This location is particularly significant as it suggests the vulnerability involves the manipulation of graphics rendering operations that could be exploited to redirect execution flow or corrupt memory structures. The faulting address controls branch selection, meaning that an attacker can manipulate conditional execution paths within the graphics processing code through carefully crafted input data, potentially leading to arbitrary code execution or system instability. This behavior aligns with CWE-129, which describes improper validation of input ranges, and represents a classic case of buffer over-read or memory corruption vulnerability.
The operational impact of this vulnerability extends beyond simple denial of service, as it could potentially enable remote code execution or system compromise. When an attacker successfully triggers this flaw, the affected XnView Classic application crashes or becomes unresponsive, causing a denial of service that prevents legitimate users from accessing image files. However, the underlying memory corruption mechanism suggests that more sophisticated attacks might be possible, particularly if the vulnerability can be chained with other exploits or used in conjunction with privilege escalation techniques. The vulnerability affects any user who opens a malicious .rle file within the XnView Classic application, making it particularly dangerous in environments where users might encounter untrusted image files. Attackers could leverage this vulnerability in phishing campaigns, social engineering attacks, or by embedding malicious files in email attachments, potentially compromising entire systems.
Mitigation strategies for CVE-2017-10766 should focus on immediate patching of the affected XnView Classic application to version 2.41 or later, which contains the necessary fixes for the input validation issues. System administrators should implement strict file validation policies that prevent automatic execution of potentially malicious image files, particularly those with .rle extensions, and consider deploying application whitelisting solutions to restrict execution of untrusted software. Network-based defenses should include content filtering mechanisms that scan for known malicious file patterns and implement sandboxing techniques for image file processing. Organizations should also consider disabling automatic image preview features in email clients and web browsers to reduce attack surface exposure. The vulnerability demonstrates the importance of proper input validation in graphics processing libraries and highlights the need for security-conscious development practices that adhere to ATT&CK framework principles for preventing code execution through input manipulation. Additionally, regular security assessments of image processing applications and comprehensive vulnerability scanning should be implemented to identify similar issues in other software components that handle external data input.