CVE-2017-15783 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 controls Branch Selection starting at CADImage+0x0000000000285ce1."
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Analysis
by VulDB Data Team • 11/29/2019
CVE-2017-15783 represents a critical vulnerability in XnView Classic for Windows version 2.43 that manifests through improper handling of maliciously crafted .dwg files. This vulnerability falls under the category of heap-based buffer overflows and memory corruption issues, specifically affecting the CADImage component within the software's image processing pipeline. The flaw occurs when the application attempts to parse malformed DWG files that contain specially crafted data structures at the faulting address, leading to unpredictable behavior and potential system instability.
The technical exploitation of this vulnerability stems from a direct manipulation of the program's execution flow through branch selection mechanisms. When XnView Classic encounters a malformed .dwg file, the CADImage module executes code at address 0x0000000000285ce1 where the faulting address controls branch selection. This creates a scenario where attacker-controlled data directly influences the program's decision-making process, potentially leading to arbitrary code execution or complete application crash. The vulnerability demonstrates characteristics consistent with CWE-121 heap-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations and manipulate program execution.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides potential attack vectors for more sophisticated exploits. An attacker could craft malicious DWG files that trigger memory corruption during image rendering, causing the application to crash or behave unpredictably. In some cases, this memory corruption could be leveraged to execute arbitrary code with the privileges of the user running XnView Classic, particularly in environments where the application is used to process untrusted files from web sources or email attachments. The vulnerability affects the software's ability to properly validate and sanitize input data, making it susceptible to manipulation through carefully constructed file formats.
Mitigation strategies for CVE-2017-15783 should focus on immediate patching of the XnView Classic application to version 2.44 or later, which contains fixes for the memory handling issues in the CADImage component. Organizations should implement strict file validation policies that prevent automatic processing of untrusted .dwg files, particularly those received from external sources. Network administrators should consider implementing file type filtering at network boundaries and deploying sandboxing solutions to isolate file processing activities. Security monitoring should include detection of unusual application behavior or crashes that could indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1203, which involves using malicious files to gain code execution through application vulnerabilities, and T1059, which covers the execution of malicious code through compromised applications. Users should also be educated about the risks of opening unknown file types and the importance of keeping software updated to address known vulnerabilities in image processing applications.