CVE-2018-14565 in THULAC
Summary
by MITRE
An issue was discovered in libthulac.so in THULAC through 2018-02-25. A heap-based buffer over-read can occur in NGramFeature::find_bases in include/cb_ngram_feature.h.
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Analysis
by VulDB Data Team • 04/25/2023
The vulnerability identified as CVE-2018-14565 represents a critical heap-based buffer over-read flaw within the THULAC natural language processing library. This issue resides in the libthulac.so shared library component and specifically affects versions through the 2018-02-25 release. The vulnerability manifests within the NGramFeature::find_bases function located in the include/cb_ngram_feature.h header file, making it a fundamental component of the library's n-gram feature extraction mechanism that processes textual data for linguistic analysis.
The technical nature of this vulnerability stems from improper bounds checking within the memory management operations of the n-gram feature extraction algorithm. When the NGramFeature::find_bases function processes input text data, it fails to adequately validate the boundaries of memory allocations, allowing for a buffer over-read condition to occur. This type of flaw enables an attacker to read data from memory locations beyond the intended buffer boundaries, potentially exposing sensitive information stored in adjacent memory segments. The heap-based nature of the vulnerability indicates that the memory allocation occurs on the heap rather than the stack, making the exploitation more complex but equally dangerous.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially enable more sophisticated attack vectors when combined with other memory corruption vulnerabilities. An attacker who successfully exploits this buffer over-read could access arbitrary memory locations, potentially retrieving confidential data, stack contents, or even executable code pointers that might lead to arbitrary code execution. The vulnerability affects applications that utilize THULAC for text processing, particularly those handling untrusted input data, making it a significant concern for systems processing sensitive textual information in natural language processing workflows.
Security practitioners should recognize this vulnerability as aligning with CWE-125, which specifically addresses out-of-bounds read conditions in software implementations. The flaw also corresponds to ATT&CK technique T1059.007, which involves the use of system commands and scripts in the exploitation of memory corruption vulnerabilities. Organizations utilizing THULAC libraries should prioritize immediate patching of affected versions, as the vulnerability represents a persistent risk to system security. Mitigation strategies should include implementing proper bounds checking in memory operations, conducting thorough code reviews of memory management functions, and employing runtime protections such as address space layout randomization and stack canaries to reduce the exploitability of such buffer over-read conditions.
The vulnerability demonstrates the critical importance of memory safety in natural language processing libraries, where text parsing and feature extraction functions often handle large volumes of data. Given that THULAC is commonly used in academic and research environments for linguistic analysis, the potential impact extends to research data integrity and the security of computational linguistics applications. Organizations should implement comprehensive vulnerability management processes that include regular updates of third-party libraries, automated security scanning of dependencies, and continuous monitoring for similar memory safety issues in their software supply chains. The presence of such vulnerabilities underscores the necessity of rigorous software testing practices, particularly for libraries handling text processing and natural language analysis where memory management complexity can introduce subtle but dangerous flaws.