Vulnerability Details : 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 category: Denial of service
Products affected by CVE-2021-43843
- cpe:2.3:a:jsx-slack_project:jsx-slack:*:*:*:*:*:node.js:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-43843
0.30%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 70 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-43843
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
5.0
|
MEDIUM | AV:N/AC:L/Au:N/C:N/I:N/A:P |
10.0
|
2.9
|
NIST | |
7.5
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
3.9
|
3.6
|
NIST | |
5.3
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
3.9
|
1.4
|
GitHub, Inc. |
CWE ids for CVE-2021-43843
-
The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.Assigned by: security-advisories@github.com (Secondary)
-
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.Assigned by: security-advisories@github.com (Secondary)
References for CVE-2021-43843
-
https://github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248q
Regular Expression Denial of Service (ReDoS) in jsx-slack · Advisory · yhatt/jsx-slack · GitHubExploit;Patch;Third Party Advisory
-
https://github.com/yhatt/jsx-slack/releases/tag/v4.5.2
Release v4.5.2 · yhatt/jsx-slack · GitHubRelease Notes;Third Party Advisory
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https://github.com/yhatt/jsx-slack/commit/46bc88391d89d5fda4ce689e18ca080bcdd29ecc
Prevent catastrophic backtracking in blockquote escape replacer · yhatt/jsx-slack@46bc883 · GitHubPatch;Third Party Advisory
-
https://github.com/yhatt/jsx-slack/security/advisories/GHSA-hp68-xhvj-x6j6
Insufficient patch for Regular Expression Denial of Service (ReDoS) to jsx-slack v4.5.1 · Advisory · yhatt/jsx-slack · GitHubExploit;Patch;Third Party Advisory
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