CVE-2018-11728 in libfsntfs
Summary
by MITRE
The libfsntfs_reparse_point_values_read_data function in libfsntfs_reparse_point_values.c in libfsntfs through 2018-04-20 allows remote attackers to cause an information disclosure (heap-based buffer over-read) via a crafted ntfs file.
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Analysis
by VulDB Data Team • 07/23/2024
The vulnerability identified as CVE-2018-11728 represents a critical heap-based buffer over-read flaw within the libfsntfs library, specifically affecting the libfsntfs_reparse_point_values_read_data function. This library serves as a crucial component for parsing NTFS file systems and is widely utilized in forensic analysis tools and system utilities that require NTFS file system interpretation. The flaw exists in the handling of reparse point values within NTFS files, where the function fails to properly validate input data length before performing memory operations. When processing a specially crafted NTFS file containing maliciously constructed reparse point data, the function attempts to read beyond the allocated buffer boundaries, resulting in information disclosure vulnerabilities that can expose sensitive data from adjacent memory regions.
The technical implementation of this vulnerability stems from inadequate bounds checking within the libfsntfs_reparse_point_values_read_data function located in libfsntfs_reparse_point_values.c. The flaw manifests when the library processes reparse point data structures within NTFS files without proper validation of the data size against the allocated buffer space. This allows attackers to craft NTFS files containing oversized reparse point values that trigger the buffer over-read condition. The heap-based nature of the vulnerability means that memory corruption occurs in the heap memory region, potentially exposing stack contents, heap metadata, or other sensitive information stored in adjacent memory locations. This type of vulnerability falls under CWE-125: "Out-of-bounds Read" and represents a classic example of how improper input validation can lead to information disclosure attacks.
The operational impact of CVE-2018-11728 extends beyond simple information disclosure, as it can provide attackers with access to sensitive data that may include system memory contents, cryptographic keys, or other confidential information stored in memory. The vulnerability is particularly concerning in forensic analysis environments where libfsntfs is commonly used to process potentially malicious NTFS files, as it could be exploited to extract sensitive information from memory during file processing operations. Attackers could leverage this vulnerability by creating specially crafted NTFS files with malicious reparse point data that, when processed by vulnerable applications, would trigger the buffer over-read and expose adjacent memory contents. This information disclosure could potentially lead to further exploitation opportunities including privilege escalation or credential theft, making the vulnerability particularly dangerous in security-sensitive environments.
Mitigation strategies for CVE-2018-11728 should focus on immediate library updates to versions that contain proper bounds checking and input validation mechanisms. System administrators and security professionals should prioritize patching all systems that utilize libfsntfs, particularly those in forensic analysis, digital forensics, or system recovery environments where NTFS file processing is common. The vulnerability can also be addressed through input sanitization at the application level by implementing additional validation checks before passing NTFS files to libfsntfs processing functions. Security monitoring should be enhanced to detect potential exploitation attempts through unusual file processing patterns or memory access anomalies. Additionally, organizations should consider implementing network segmentation and access controls to limit exposure to potentially malicious NTFS files, while also maintaining regular vulnerability assessments to identify other potential buffer overflow or memory corruption vulnerabilities in similar file system parsing libraries. The ATT&CK framework categorizes this type of vulnerability under T1059.007: "Command and Scripting Interpreter: PowerShell" and T1566.001: "Phishing: Spearphishing Attachment" when considering how attackers might deliver malicious NTFS files to target systems, though the specific exploitation pathway focuses on the memory corruption aspect rather than traditional command execution.