CVE-2017-11328 in YARA
Summary
by MITRE
Heap buffer overflow in the yr_object_array_set_item() function in object.c in YARA 3.x allows a denial-of-service attack by scanning a crafted .NET file.
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Analysis
by VulDB Data Team • 12/12/2022
The vulnerability identified as CVE-2017-11328 represents a critical heap buffer overflow flaw within the YARA threat detection engine version 3.x. This vulnerability specifically affects the yr_object_array_set_item() function located in the object.c source file, which serves as a fundamental component for managing object arrays within the YARA framework. The flaw manifests when YARA processes crafted .NET files during malware scanning operations, creating a scenario where an attacker can deliberately construct malicious input that triggers the buffer overflow condition.
The technical implementation of this vulnerability stems from inadequate bounds checking within the yr_object_array_set_item() function. When YARA encounters a specially crafted .NET file, the parsing logic fails to properly validate array indices and memory allocation boundaries before attempting to store or modify array elements. This deficiency allows an attacker to manipulate the memory layout by providing input data that causes the function to write beyond the allocated heap buffer space, potentially leading to memory corruption and system instability. The vulnerability operates at the memory management level, where improper handling of array operations in the YARA engine's object model creates opportunities for malicious input to disrupt normal program execution flow.
The operational impact of CVE-2017-11328 extends beyond simple denial-of-service conditions, as it represents a significant security risk for organizations relying on YARA for malware detection and threat hunting activities. When exploited, this vulnerability can cause YARA processes to crash or become unresponsive, effectively disabling threat detection capabilities during critical security operations. The vulnerability is particularly concerning because it can be triggered through routine file scanning operations, meaning that legitimate security workflows become compromised when processing seemingly benign .NET files. This creates a scenario where defensive security tools themselves become attack vectors, undermining the integrity of the overall security infrastructure. The vulnerability maps to CWE-121, heap-based buffer overflow, and aligns with ATT&CK technique T1059.001 for executing malicious code through file scanning operations.
Organizations should implement immediate mitigations including updating to YARA versions that have addressed this vulnerability, typically those released after the initial disclosure. The recommended approach involves deploying patched versions of YARA where the yr_object_array_set_item() function has been modified to include proper bounds checking and memory validation before array operations. Additionally, implementing input validation measures that filter or sanitize .NET files before processing can provide an additional layer of protection. Security teams should also consider monitoring for unusual YARA process behavior or crashes that might indicate exploitation attempts. The vulnerability demonstrates the importance of robust memory management practices in security tools and highlights the need for comprehensive testing of input handling routines in threat detection software, particularly when dealing with complex file formats like .NET assemblies that contain intricate metadata structures.