CVE-2017-10757 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 ntdll_77df0000!RtlpCoalesceFreeBlocks+0x00000000000001b6."
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Analysis
by VulDB Data Team • 10/22/2019
The vulnerability identified as CVE-2017-10757 affects XnView Classic for Windows version 2.40 and represents a critical denial of service condition that can be triggered through maliciously crafted .rle files. This flaw exists within the image processing pipeline of the software when handling Run-Length Encoded format files, which are commonly used for storing bitmap images with compressed data. The vulnerability stems from improper input validation and memory management during the parsing of RLE file structures, creating a condition where an attacker can manipulate the software's execution flow through carefully constructed file content.
The technical root cause of this vulnerability lies in the ntdll.dll component of the Windows operating system, specifically within the RtlpCoalesceFreeBlocks function at address ntdll_77df0000!RtlpCoalesceFreeBlocks+0x00000000000001b6. This function is responsible for managing heap memory operations and consolidating free memory blocks during garbage collection processes. When XnView Classic processes a malformed .rle file, it triggers a fault in the memory management system where data from a faulting address directly controls branch selection within the Windows kernel. This creates a scenario where arbitrary memory values can influence program execution paths, potentially leading to unpredictable behavior including system crashes or application hangs.
The operational impact of this vulnerability extends beyond simple denial of service as it represents a potential vector for more sophisticated attacks. While the primary effect manifests as application instability and system crashes, the underlying memory corruption vulnerability could theoretically be exploited to achieve arbitrary code execution depending on the system configuration and memory layout. The vulnerability affects the core functionality of XnView Classic's image processing engine, making it impossible for users to safely open or process potentially malicious image files. This impacts not only individual users but also organizations that rely on image viewing applications for document processing, image management, or digital asset handling workflows.
Security professionals should note that this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write vulnerabilities. The flaw also maps to ATT&CK technique T1203, which involves exploitation of system memory for code execution, and T1059, which covers command and scripting interpreters. Organizations should implement immediate mitigations including disabling support for .rle file formats within XnView Classic, updating to patched versions of the software, and implementing network-based restrictions that prevent automatic processing of potentially malicious image files. Additionally, users should be educated about the risks of opening untrusted image files and the importance of keeping software updated to prevent exploitation of known vulnerabilities. The vulnerability demonstrates the critical importance of proper input validation in multimedia processing applications and the need for robust memory management practices in software that handles untrusted data formats.