CVE-2017-15776 in XnView Classic
Summary
by MITRE
XnView Classic for Windows Version 2.43 allows attackers to cause a denial of service or possibly have unspecified other impact via a crafted .dwg file, related to "Data from Faulting Address may be used as a return value starting at CADImage+0x0000000000285ec1."
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Analysis
by VulDB Data Team • 11/28/2019
The vulnerability CVE-2017-15776 represents a critical denial of service condition affecting XnView Classic for Windows version 2.43 and potentially earlier releases. This flaw manifests when the application processes specially crafted .dwg files, which are AutoCAD drawing files commonly used in engineering and architectural design. The vulnerability stems from improper handling of malformed data structures within these CAD files, creating a scenario where the application fails to properly validate input before processing. The specific technical indicator points to a faulting address at CADImage+0x0000000000285ec1, suggesting that memory corruption occurs during the parsing of CAD image data structures, which can lead to unpredictable behavior and system instability.
The technical exploitation of this vulnerability involves crafting a malicious .dwg file that triggers a memory access violation or stack corruption during the image rendering process. When XnView Classic attempts to parse and display the malformed file, it encounters invalid data at the specified memory address, causing the application to crash or enter an undefined state. This type of vulnerability falls under the category of memory corruption issues, which are classified as CWE-125 in the Common Weakness Enumeration system, representing out-of-bounds read conditions. The flaw demonstrates poor input validation and error handling practices, where the application does not adequately sanitize or verify the integrity of external data before processing.
The operational impact of this vulnerability extends beyond simple application crashes, as it can potentially enable more sophisticated attacks depending on the execution environment. An attacker could leverage this vulnerability to disrupt legitimate users' ability to view CAD files, effectively creating a denial of service condition that impacts productivity in engineering and design workflows. The unspecified other impacts mentioned in the CVE description suggest that under certain conditions, this vulnerability might potentially allow for privilege escalation or code execution, though this remains unconfirmed. The vulnerability affects users who rely on XnView Classic for viewing CAD files, making it particularly concerning in professional environments where such files are frequently processed and shared. Organizations using this software in mission-critical applications face potential operational disruptions that could impact design reviews, collaboration workflows, and project timelines.
Mitigation strategies for CVE-2017-15776 should focus on immediate software updates and defensive measures to prevent exploitation. The primary recommendation involves upgrading to the latest version of XnView Classic where this vulnerability has been addressed through proper input validation and memory management improvements. System administrators should implement network segmentation and file validation policies to prevent unauthorized users from uploading potentially malicious .dwg files to shared systems. Additionally, users should avoid opening .dwg files from untrusted sources and implement sandboxing techniques when processing unknown CAD files. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving execution through file processing and privilege escalation through application flaws, making it important for security teams to monitor for potential exploitation attempts. The vulnerability also highlights the importance of secure coding practices and input validation, particularly in applications that process complex file formats, as it demonstrates how seemingly benign file processing operations can become attack vectors when proper validation is absent.