CVE-2017-10736 in XnView Classic
Summary
by MITRE
XnView Classic for Windows Version 2.40 allows attackers to execute arbitrary code or cause a denial of service via a crafted .rle file, related to a "User Mode Write AV starting at msvcrt!_VEC_memzero+0x000000000000006a."
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Analysis
by VulDB Data Team • 06/07/2020
CVE-2017-10736 represents a critical buffer overflow vulnerability affecting XnView Classic for Windows version 2.40 that stems from improper handling of malformed .rle image files. This vulnerability manifests as a user mode write access violation within the msvcrt!_VEC_memzero function, indicating that the application fails to properly validate input data when processing RLE (Run-Length Encoded) image format files. The flaw occurs during the memory zeroing operation where the application attempts to write to memory locations that are either unallocated or improperly validated, creating a potential execution path for malicious code injection.
The technical nature of this vulnerability places it squarely within the CWE-121 category of stack-based buffer overflow conditions, though the specific manifestation in this case involves heap corruption through improper memory management during file parsing operations. The ATT&CK framework categorizes this as a code injection technique under the T1059.007 sub-technique, specifically targeting application execution through malformed file inputs. The vulnerability's exploitation requires an attacker to craft a malicious .rle file that triggers the buffer overflow condition when XnView Classic attempts to parse and render the image, potentially leading to arbitrary code execution with the privileges of the affected user.
Operational impact of this vulnerability extends beyond simple denial of service to encompass full system compromise potential. When an unsuspecting user opens a crafted .rle file within XnView Classic, the application crashes or may execute malicious code, depending on exploitation success. This makes the vulnerability particularly dangerous in enterprise environments where users may encounter such files through email attachments, web downloads, or file sharing systems. The vulnerability affects Windows systems running XnView Classic version 2.40 and earlier, representing a significant security gap in image processing applications that handle multiple file formats.
Mitigation strategies should focus on immediate patching of the affected software to version 2.41 or later, which contains the necessary memory validation fixes. Additionally, organizations should implement strict file validation policies that prevent execution of untrusted image files through standard applications. Network-based protections can include content filtering systems that scan for suspicious file patterns and prevent download of potentially malicious .rle files. Users should be educated about the dangers of opening untrusted image files and the importance of keeping software updated. Security monitoring should include detection of异常 file processing activities and memory access violations in image processing applications. The vulnerability demonstrates the critical importance of proper input validation in multimedia applications and highlights the need for robust memory safety mechanisms in software that processes external data formats, particularly in the context of the principle of least privilege and defense in depth security strategies.