CVE - CVE-2021-43854

CVE-ID
CVE-2021-43854	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Versions prior to 3.6.5 are vulnerable to regular expression denial of service (ReDoS) attacks. The vulnerability is present in PunktSentenceTokenizer, sent_tokenize and word_tokenize. Any users of this class, or these two functions, are vulnerable to the ReDoS attack. In short, a specifically crafted long input to any of these vulnerable functions will cause them to take a significant amount of execution time. If your program relies on any of the vulnerable functions for tokenizing unpredictable user input, then we would strongly recommend upgrading to a version of NLTK without the vulnerability. For users unable to upgrade the execution time can be bounded by limiting the maximum length of an input to any of the vulnerable functions. Our recommendation is to implement such a limit.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
CONFIRM:https://github.com/nltk/nltk/security/advisories/GHSA-f8m6-h2c7-8h9x URL:https://github.com/nltk/nltk/security/advisories/GHSA-f8m6-h2c7-8h9x MISC:https://github.com/nltk/nltk/commit/1405aad979c6b8080dbbc8e0858f89b2e3690341 URL:https://github.com/nltk/nltk/commit/1405aad979c6b8080dbbc8e0858f89b2e3690341 MISC:https://github.com/nltk/nltk/issues/2866 URL:https://github.com/nltk/nltk/issues/2866 MISC:https://github.com/nltk/nltk/pull/2869 URL:https://github.com/nltk/nltk/pull/2869
Assigning CNA
GitHub (maintainer security advisories)
Date Record Created
20211116	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20211116)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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