Resource exhaustion in Jsx-Slack Project
CVE-2021-43843
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.019 (77.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Jsx-slack_project Jsx-slack
- Yhatt Jsx-slack — versions < 4.5.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Patch, Third Party Advisory)
- security-advisories@github.com (Exploit, Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2021-43843?
- CVE-2021-43843 is a medium-severity vulnerability in Jsx-Slack Project, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2021-12-20.
- How severe is CVE-2021-43843?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2021-43843 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.