CVE-2021-27405 is a medium-severity (CVSS 4.3) Uncontrolled Resource Consumption vulnerability in @progfay/scrapbox-parser. A fix is available for @progfay/scrapbox-parser — see the affected versions and patch details below.
Regular expression Denial of Service in @progfay/scrapbox-parser
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-27405 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
@progfay/scrapbox-parser📦@progfay/scrapbox-parserReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A Regular expression Denial of Service flaw was found in the @progfay/scrapbox-parser package before 6.0.3, 7.0.2 for Node.js. The attacker that is able to be parsed a specially crafted text may cause the application to consume an excessive amount of CPU.
Patches
Upgrade to version 6.0.3, 7.0.2 or later.
Workarounds
Avoid to parse text with a lot of [ chars.
References
- https://github.com/progfay/scrapbox-parser/pull/519
- https://github.com/progfay/scrapbox-parser/pull/539
- https://github.com/progfay/scrapbox-parser/pull/540
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=2021-27405
- https://snyk.io/vuln/SNYK-JS-PROGFAYSCRAPBOXPARSER-1076803
For more information
If you have any questions or comments about this advisory:
- Open an issue in github.com/progfay/scrapbox-parser
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @progfay/scrapbox-parser | all versions | 6.0.3npm install @progfay/scrapbox-parser@6.0.3 |
| 📦npm | @progfay/scrapbox-parser | ≥ 7.0.0&&< 7.0.2 | 7.0.2npm install @progfay/scrapbox-parser@7.0.2 |
Affected Products
scrapbox-parserscrapbox-parser_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @progfay/scrapbox-parser, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @progfay/scrapbox-parser to 6.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-27405 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2021-27405 in your dependencies?
Find it across npm, including transitive dependencies.