CVE-2018-15176 in XnView
Summary
by MITRE
XnView 2.45 allows remote attackers to cause a denial of service (User Mode Write AV starting at MSVCR120!memcpy+0x0000000000000074 and application crash) or possibly have unspecified other impact via a crafted RLE file.
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Analysis
by VulDB Data Team • 03/14/2020
CVE-2018-15176 represents a critical vulnerability in XnView version 2.45 that manifests as a heap-based buffer overflow during the processing of specially crafted RLE (Run-Length Encoded) image files. This vulnerability falls under the CWE-121 heap-based buffer overflow category and specifically exploits improper bounds checking during memory operations. The flaw occurs when the application attempts to copy data using memcpy function from the MSVCR120 runtime library, where the write access violation happens at offset 0x74 within the memcpy implementation, causing an application crash and potential denial of service condition.
The technical exploitation of this vulnerability requires an attacker to craft a malicious RLE file that triggers an out-of-bounds memory write operation when XnView attempts to decode and render the image. The vulnerability is particularly concerning because it can be triggered through normal file processing operations without requiring any special privileges or user interaction beyond opening the malicious file. The heap corruption occurs during the decompression phase of RLE encoding, where the application fails to validate the length of data being copied into allocated memory buffers, leading to a write access violation that terminates the application process.
From an operational perspective, this vulnerability creates significant risk for users who may encounter maliciously crafted RLE files through email attachments, web downloads, or file sharing platforms. The impact extends beyond simple denial of service as the vulnerability could potentially be leveraged for more sophisticated attacks, especially when combined with other memory corruption vulnerabilities. The application crash represents a complete service interruption for the affected user, potentially disrupting workflows in environments where XnView is used for image processing tasks. According to ATT&CK framework, this vulnerability maps to T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) through potential exploitation paths that could lead to arbitrary code execution.
Mitigation strategies should include immediate patching of XnView to version 2.46 or later, which contains the necessary fixes for the RLE decoding routines. Organizations should implement strict file validation policies for incoming RLE files, particularly those from untrusted sources, and consider deploying sandboxing solutions for image file processing. Network administrators should monitor for suspicious file types and implement email filtering rules that block potentially malicious RLE files. Additionally, users should be educated about the risks of opening untrusted image files and the importance of keeping software updated. The vulnerability demonstrates the importance of proper input validation and bounds checking in image processing libraries, as highlighted by CWE-125 (Out-of-bounds Read) and CWE-787 (Out-of-bounds Write) categories that emphasize the need for robust memory management practices in multimedia applications.