CVE-2017-10783 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!RtlpFreeHeap+0x0000000000000393."
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Analysis
by VulDB Data Team • 10/22/2019
The vulnerability identified as CVE-2017-10783 affects XnView Classic for Windows version 2.40 and represents a critical denial of service condition that could potentially lead to more severe consequences. This flaw manifests when the application processes a specially crafted .rle file, which stands for Run-Length Encoded format commonly used for image data compression. The vulnerability stems from improper handling of memory allocation and deallocation within the application's image processing pipeline, specifically involving the Windows ntdll library functions that manage heap memory operations.
The technical root cause of this vulnerability lies in the way XnView Classic handles memory management when processing malformed .rle files. The fault occurs at the ntdll_77df0000!RtlpFreeHeap+0x0000000000000393 memory address, indicating that the application's heap management routines are susceptible to manipulation through crafted input data. This particular memory address represents a function within the Windows runtime library responsible for freeing heap memory, and when corrupted by malicious input, it can cause unpredictable behavior including application crashes or system instability. The vulnerability demonstrates characteristics consistent with heap-based buffer overflows and memory corruption issues that fall under CWE-122 Heap-based Buffer Overflow, which is classified as a fundamental memory safety issue.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a potential entry point for more sophisticated attacks. When an attacker successfully exploits this vulnerability through a crafted .rle file, the application may crash or become unresponsive, effectively denying users access to the image viewing functionality. However, the potential for unspecified other impacts suggests that this vulnerability could be leveraged to execute arbitrary code or escalate privileges, particularly if the memory corruption leads to control flow hijacking. The vulnerability affects any system running XnView Classic 2.40 and could be exploited in environments where users might encounter untrusted image files, such as email attachments, web downloads, or file sharing networks.
Security professionals should recognize this vulnerability as part of the broader category of software exploitation techniques that target memory management functions, which aligns with ATT&CK technique T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation. The vulnerability's exploitation potential makes it particularly dangerous in enterprise environments where image viewing applications are commonly used and may be exposed to untrusted content. Organizations should implement immediate mitigations including updating to the latest version of XnView Classic, implementing strict file validation controls, and deploying network-based intrusion detection systems to monitor for exploitation attempts. Additionally, user education regarding the dangers of opening untrusted image files remains critical in preventing successful exploitation of this vulnerability.
The vulnerability demonstrates the importance of proper input validation and memory management in image processing applications, highlighting how seemingly benign file format handling can become a vector for serious security incidents. The specific mention of ntdll functions suggests that the vulnerability may be exploitable through techniques that manipulate Windows heap management, potentially leading to privilege escalation or code execution. Given the age of the affected version and the nature of the vulnerability, organizations should prioritize immediate remediation and consider implementing additional security controls such as application whitelisting, sandboxing of image processing applications, and regular security assessments of image handling components within their environments.