CVE-2018-11206 in HDF5
Summary
by MITRE
A out of bounds read was discovered in H5O_fill_new_decode and H5O_fill_old_decode in H5Ofill.c in the HDF HDF5 1.10.2 library. It could allow a remote denial of service or information disclosure attack.
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Analysis
by VulDB Data Team • 02/06/2020
The vulnerability identified as CVE-2018-11206 represents a critical out-of-bounds read condition within the HDF5 library version 1.10.2, specifically affecting the H5O_fill_new_decode and H5O_fill_old_decode functions located in the H5Ofill.c source file. This flaw arises from insufficient input validation during the decoding process of HDF5 file objects, particularly when handling fill values within dataset objects. The vulnerability manifests when the library processes malformed or specially crafted HDF5 files that contain improperly structured fill value data, leading to memory access violations beyond the allocated buffer boundaries.
The technical implementation of this vulnerability stems from the lack of proper bounds checking in the decode functions that handle fill value information stored within HDF5 objects. When these functions attempt to read data from memory locations that exceed the intended buffer limits, they may access adjacent memory regions that could contain sensitive information or cause the application to crash. This out-of-bounds read condition can be triggered through the parsing of malformed HDF5 files that contain crafted fill value structures, making it particularly dangerous for applications that process untrusted HDF5 data from external sources. The vulnerability operates at the level of the HDF5 object header decoding mechanism, where fill values are used to specify default values for dataset elements that have not yet been written to disk.
From an operational perspective, this vulnerability presents significant risks to systems that utilize the HDF5 library for data processing, particularly in environments where untrusted data sources are common. The potential impact includes remote denial of service attacks where maliciously crafted HDF5 files can cause application crashes or system instability, as well as information disclosure scenarios where adjacent memory contents may be inadvertently exposed to attackers. The vulnerability is particularly concerning in web applications, scientific computing environments, and data processing pipelines that routinely handle external data inputs, as these systems may be susceptible to exploitation through simple file upload or data import operations. The remote attack vector means that adversaries can potentially exploit this vulnerability without requiring local system access, making it a serious threat to networked applications.
The security implications of CVE-2018-11206 align with CWE-125 Out-of-bounds Read classification, which specifically addresses situations where programs read memory locations beyond the intended buffer boundaries. This vulnerability also maps to ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, as it affects applications that process JavaScript-based data formats that may utilize HDF5 libraries. Additionally, the vulnerability can be categorized under T1499.004 Endpoint Denial of Service due to its potential to cause system instability through resource exhaustion or application crashes. Organizations should prioritize patching affected systems and implementing proper input validation measures to prevent exploitation of this vulnerability, particularly in environments where external data processing is common. The recommended mitigation strategy includes upgrading to HDF5 library versions that contain the fix for this vulnerability, implementing strict file format validation, and establishing network segmentation to limit exposure of vulnerable applications to untrusted data sources.