CVE-2021-43843
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.92%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.92% probability · 79th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-1333
- Affected
- jsx-slack project/jsx-slack
- Source
- security-advisories@github.com
References
- https://github.com/yhatt/jsx-slack/commit/46bc88391d89d5fda4ce689e18ca080bcdd29eccPatch, Third Party Advisory
- https://github.com/yhatt/jsx-slack/releases/tag/v4.5.2Release Notes, Third Party Advisory
- https://github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248qExploit, Patch, Third Party Advisory
- https://github.com/yhatt/jsx-slack/security/advisories/GHSA-hp68-xhvj-x6j6Exploit, Patch, Third Party Advisory
- https://github.com/yhatt/jsx-slack/commit/46bc88391d89d5fda4ce689e18ca080bcdd29eccPatch, Third Party Advisory
- https://github.com/yhatt/jsx-slack/releases/tag/v4.5.2Release Notes, Third Party Advisory
- https://github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248qExploit, Patch, Third Party Advisory
- https://github.com/yhatt/jsx-slack/security/advisories/GHSA-hp68-xhvj-x6j6Exploit, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.