CVE-2017-10765 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 IMM32!ImmLockImeDpi+0x0000000000000050."
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Analysis
by VulDB Data Team • 10/22/2019
CVE-2017-10765 represents a critical vulnerability in XnView Classic for Windows version 2.40 that stems from improper handling of maliciously crafted .rle files during the image processing pipeline. This vulnerability specifically manifests within the IMM32.dll component which is responsible for ime (input method editor) functionality and text input handling in windows operating systems. The flaw occurs when the application attempts to process a specially crafted .rle file that contains malformed data structures which ultimately leads to a faulting address within the ImmLockImeDpi function. The vulnerability is classified as a control flow hijacking issue where attacker-controlled data from the faulting address directly influences branch selection logic within the IMM32!ImmLockImeDpi function at offset 0x50, creating a potential pathway for arbitrary code execution or system instability.
The technical implementation of this vulnerability involves a classic buffer overflow or memory corruption scenario where the .rle file format parser fails to properly validate input data before processing. When XnView Classic attempts to load the malicious file, it triggers a cascade of memory operations that result in an invalid memory access pattern. The specific address mentioned in the vulnerability description points to a location within the windows IMM32.dll library where the application's fault handling mechanism encounters corrupted data that it cannot properly process. This creates a condition where the program's execution flow becomes unpredictable and potentially exploitable. The vulnerability exhibits characteristics consistent with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write vulnerabilities, both of which are fundamental memory safety issues that can lead to privilege escalation or denial of service conditions.
From an operational impact perspective, this vulnerability presents significant risks to end users who may unknowingly open maliciously crafted .rle files through XnView Classic. The denial of service aspect means that legitimate users could experience complete application crashes or system instability when processing these files, effectively rendering the image viewer unusable. The unspecified other impacts referenced in the CVE description suggest potential for more severe consequences including privilege escalation or code execution within the context of the running application. Attackers could leverage this vulnerability to deliver payloads through social engineering campaigns where users are tricked into opening seemingly legitimate image files. The vulnerability is particularly concerning because it operates at the application level within a commonly used image viewer, making it an attractive target for attackers seeking to compromise user systems through image-based attack vectors.
Mitigation strategies for CVE-2017-10765 should prioritize immediate software updates from the vendor, as version 2.40 of XnView Classic was vulnerable and subsequent releases addressed the issue. System administrators should implement strict file validation policies that prevent users from opening untrusted image files, particularly those with .rle extensions. Network-based mitigations could include implementing sandboxing mechanisms for image processing operations and deploying intrusion detection systems that monitor for suspicious file handling patterns. The vulnerability's exploitation aligns with ATT&CK technique T1068, which covers local privilege escalation through application vulnerabilities, and T1203, which describes exploitation of software vulnerabilities for execution. Users should be educated about the risks of opening files from untrusted sources and the importance of keeping software updated. Additionally, implementing application whitelisting policies that restrict execution of vulnerable applications or their components can provide defense in depth against exploitation attempts. Organizations should also consider deploying endpoint protection solutions that can detect and block malicious file processing activities that match the patterns associated with this vulnerability.