CVE-2018-11099 in VCFtools
Summary
by MITRE
The header::add_INFO_descriptor function in header.cpp in VCFtools 0.1.15 allows remote attackers to cause information disclosure (heap-based buffer over-read) via a crafted vcf file.
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Analysis
by VulDB Data Team • 03/14/2023
The vulnerability identified as CVE-2018-11099 represents a critical heap-based buffer over-read flaw within VCFtools version 0.1.15, specifically within the header::add_INFO_descriptor function located in header.cpp. This issue arises from insufficient input validation and boundary checking when processing Variant Call Format files, which are commonly used in genomic data analysis. The vulnerability enables remote attackers to craft malicious VCF files that trigger memory access violations, potentially exposing sensitive information stored in adjacent memory regions. Such information disclosure could include system memory contents, internal data structures, or other confidential information that may be accessible through the buffer over-read condition.
The technical implementation of this vulnerability stems from improper handling of descriptor information within VCF files, where the add_INFO_descriptor function fails to properly validate the length and structure of incoming data. When processing malformed VCF files containing crafted INFO descriptors, the function attempts to read beyond the allocated buffer boundaries, creating a heap-based buffer over-read condition. This type of vulnerability falls under CWE-121, which categorizes heap-based buffer overflows as a significant class of memory safety issues. The flaw is particularly dangerous in genomic analysis environments where VCF files are frequently exchanged between researchers and institutions, as attackers can exploit this vulnerability through seemingly legitimate file processing operations.
The operational impact of CVE-2018-11099 extends beyond simple information disclosure to potentially enable more sophisticated attacks within genomic analysis workflows. In environments where VCFtools processes large volumes of genomic data from multiple sources, an attacker could exploit this vulnerability to extract sensitive information from memory, potentially including user credentials, system configurations, or proprietary research data. The vulnerability is particularly concerning in research institutions and clinical genomics settings where data confidentiality is paramount. Additionally, this issue could be leveraged as a stepping stone for further exploitation, as the information disclosure might reveal memory layout details that could aid in developing more advanced attacks against the same system or related components.
Mitigation strategies for CVE-2018-11099 should prioritize immediate patching of VCFtools to version 0.1.16 or later, which includes proper input validation and boundary checking mechanisms. Organizations should implement strict input validation policies for all VCF files processed through VCFtools, including automated scanning for malformed descriptors and implementing sandboxed processing environments. The vulnerability's classification under ATT&CK technique T1059.007 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) highlights the need for comprehensive network monitoring and file integrity verification systems. Security teams should also consider implementing network segmentation to limit exposure of genomic analysis systems and establish robust incident response procedures for handling potential exploitation attempts. Organizations should conduct thorough vulnerability assessments to identify all systems running affected versions of VCFtools and ensure proper access controls are implemented to minimize the attack surface.