CVE-2018-17435 in HDF5
Summary
by MITRE
A heap-based buffer over-read in H5O_attr_decode() in H5Oattr.c in the HDF HDF5 through 1.10.3 library allows attackers to cause a denial of service via a crafted HDF5 file. This issue was triggered while converting an HDF file to GIF file.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 03/27/2020
The vulnerability identified as CVE-2018-17435 represents a critical heap-based buffer over-read condition within the HDF5 library's attribute decoding functionality. This flaw exists in the H5O_attr_decode() function located in the H5Oattr.c source file and affects HDF5 versions through 1.10.3. The vulnerability manifests when processing specially crafted HDF5 files that contain malformed attribute data structures, creating a scenario where the library attempts to read memory beyond the allocated buffer boundaries. The issue specifically arises during the conversion process from HDF format to GIF format, indicating that the vulnerability is triggered by the library's handling of attribute metadata during file format transformations.
The technical exploitation of this vulnerability occurs through a heap-based buffer over-read condition that can lead to unpredictable behavior and system instability. When the H5O_attr_decode() function processes malformed attribute data, it fails to properly validate the bounds of memory allocations, allowing subsequent memory reads to access uninitialized or previously freed memory regions. This type of vulnerability falls under CWE-125, which specifically addresses out-of-bounds read conditions in software implementations. The heap-based nature of the over-read indicates that the vulnerable code operates on dynamically allocated memory blocks, making the exploitation potentially more complex and less predictable than stack-based buffer overflows.
The operational impact of CVE-2018-17435 extends beyond simple denial of service to potentially enable more sophisticated attack vectors. While the primary effect is a denial of service condition that can cause applications using the HDF5 library to crash or become unresponsive, the underlying memory corruption could theoretically be exploited to achieve arbitrary code execution under certain conditions. Attackers could craft malicious HDF5 files designed to trigger this vulnerability when processed by applications that utilize the affected library, potentially leading to system compromise or data corruption. The vulnerability's trigger during file format conversion highlights its relevance in environments where automated processing of scientific data files occurs, such as research institutions, data analysis platforms, and scientific computing environments that rely heavily on HDF5 for data storage and exchange.
Mitigation strategies for CVE-2018-17435 should focus on immediate patching of affected systems and implementation of input validation controls. Organizations should prioritize updating to HDF5 versions 1.10.4 or later, where this vulnerability has been addressed through improved bounds checking and memory validation mechanisms. Additionally, implementing strict file format validation procedures and sandboxing techniques when processing external HDF5 files can provide defense-in-depth protection. Security controls should include monitoring for unusual application behavior or crashes during file processing operations, as these may indicate exploitation attempts. The vulnerability demonstrates the importance of robust input validation in scientific computing libraries and aligns with ATT&CK technique T1203, which covers legitimate programs that are used for exploitation purposes. Organizations should also consider implementing automated vulnerability scanning tools that can detect and prevent processing of potentially malicious HDF5 files within their environments.