CVEvulnerability

CVE-2021-43843

7.5 HIGH Published 2021-12-20 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-12-20
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected])
5.0 MEDIUM — AV:N/AC:L/Au:N/C:N/I:N/A:P
Weaknesses
CWE-1333, CWE-400

Description

jsx-slack is a package for building JSON objects for Slack block kit surfaces from JSX. The maintainers found the patch for CVE-2021-43838 in jsx-slack v4.5.1 is insufficient tfor protection from a Regular Expression Denial of Service (ReDoS) attack. If an attacker can put a lot of JSX elements into `<blockquote>` tag _with including multibyte characters_, an internal regular expression for escaping characters may consume an excessive amount of computing resources. v4.5.1 passes the test against ASCII characters but misses the case of multibyte characters. jsx-slack v4.5.2 has updated regular expressions for escaping blockquote characters to prevent catastrophic backtracking. It is also including an updated test case to confirm rendering multiple tags in `<blockquote>` with multibyte characters.

Affected configurations

• jsx-slack project jsx-slack (< 4.5.2)

Related

Weakness · CWE (2)

  • CWE-1333 Inefficient Regular Expression Complexity weakness
  • CWE-400 Uncontrolled Resource Consumption weakness

References