CVE-2017-10763 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!LdrpFindLoadedDllByHandle+0x0000000000000031."
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Analysis
by VulDB Data Team • 10/22/2019
The vulnerability identified as CVE-2017-10763 affects XnView Classic for Windows version 2.40 and represents a critical security flaw that could enable attackers to execute denial of service attacks or potentially achieve unspecified secondary impacts through manipulation of specially crafted .rle files. This vulnerability specifically targets the application's handling of RLE (Run-Length Encoded) image format data, which is commonly used for compressed image storage in various graphics applications. The flaw manifests within the ntdll component of the Windows operating system, specifically at the LdrpFindLoadedDllByHandle function where faulting address data influences branch selection behavior.
The technical nature of this vulnerability stems from improper input validation and memory management within XnView's image parsing routines. When processing maliciously constructed .rle files, the application fails to properly validate the structure and content of the encoded data, leading to unpredictable execution paths within the underlying Windows loader mechanism. The vulnerability occurs at the ntdll_77df0000!LdrpFindLoadedDllByHandle+0x0000000000000031 address, indicating that attackers can manipulate the faulting address to control program flow and potentially redirect execution to arbitrary code locations. This type of vulnerability falls under the CWE-125 Out-of-bounds Read classification, as the application attempts to access memory locations beyond the intended boundaries of the RLE data structure.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it could potentially enable more sophisticated attack vectors. An attacker who successfully exploits this vulnerability could cause the XnView application to crash or hang, effectively denying users access to image viewing functionality. However, the unspecified other impacts suggest that the vulnerability might also provide opportunities for privilege escalation or code execution under certain conditions. The attack requires minimal user interaction since simply opening a malicious .rle file within XnView Classic would trigger the vulnerability, making it particularly dangerous in environments where users might encounter untrusted image files.
Security professionals should consider this vulnerability in the context of the MITRE ATT&CK framework, particularly under the T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter tactics. The vulnerability represents a classic buffer over-read scenario that can be leveraged to manipulate program execution flow and potentially establish persistent access to affected systems. Organizations using XnView Classic should immediately implement mitigations including restricting user access to potentially malicious files, implementing file type restrictions, and ensuring all systems are updated with the latest security patches. The vulnerability demonstrates the importance of robust input validation and proper error handling in multimedia applications, as these types of applications often process untrusted data from external sources without adequate security controls.