CVE-2021-43854

描述

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.

如何修補 CVE-2021-43854

要修補 CVE-2021-43854,請將受影響套件升級到下列已修補版本。

• —升級至 3.6.6 或更新版本

CVE-2021-43854 正在被利用嗎?

低 — EPSS 為 2.7%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• from 0, < 3.6.6

CVSS 分數

參考連結(7)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-43854
• PATCHgithub.com/nltk/nltk
• WEBgithub.com/nltk/nltk/commit/1405aad979c6b8080dbbc8e0858f89b2e3690341
• WEBgithub.com/nltk/nltk/issues/2866
• WEBgithub.com