CVE-2021-43854

Katalog CVE

CVSS 7.5 · High EPSS 2,6%

Kerentanan Uncontrolled Resource Consumption pada nltk. Skor CVSS 3.1 7.5 (High) menurut github.com.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD

23 Desember 2021

Terakhir diubah

17 Juni 2026

Status NVD

Modified

CVSS 3.1

7.5 (High), sumber github.com
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-400: Uncontrolled Resource Consumption

EPSS (30 hari)

2,6% peluang dieksploitasi; lebih tinggi dari 84,9% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://github.com/nltk/nltk/commit/1405aad979c6b8080dbbc8e0858f89b2e3690341 patch · advisory pihak ketiga
• https://github.com/nltk/nltk/issues/2866 exploit · issue tracking · patch · advisory pihak ketiga
• https://github.com/nltk/nltk/pull/2869 exploit · patch · advisory pihak ketiga
• https://github.com/nltk/nltk/security/advisories/GHSA-f8m6-h2c7-8h9x exploit · patch · advisory pihak ketiga