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Fencer Intel
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GHSA-xffm-g5w8-qvg7 json

@eslint/plugin-kit is vulnerable to Regular Expression Denial of Service attacks through ConfigCommentParser

published last yr. modified 2mo ago

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

### Summary

The `ConfigCommentParser#parseJSONLikeConfig` API is vulnerable to a Regular Expression Denial of Service (ReDoS) attack in its only argument.

### Details

The regular expression at [packages/plugin-kit/src/config-comment-parser.js:158](https://github.com/eslint/rewrite/blob/bd4bf23c59f0e4886df671cdebd5abaeb1e0d916/packages/plugin-kit/src/config-comment-parser.js#L158) is vulnerable to a quadratic runtime attack because the grouped expression is not anchored. This can be solved by prepending the regular expression with `[^-a-zA-Z0-9/]`.

### PoC

```javascript const { ConfigCommentParser } = require("@eslint/plugin-kit");

const str = `${"A".repeat(1000000)}?: 1 B: 2`;

console.log("start") var parser = new ConfigCommentParser(); console.log(parser.parseJSONLikeConfig(str)); console.log("end")

// run `npm i @eslint/plugin-kit@0.3.3` and `node attack.js` // then the program will stuck forever with high CPU usage ```

### Impact

This is a Regular Expression Denial of Service attack which may lead to blocking execution and high CPU usage.

Patch / fix

  • npm @eslint/plugin-kit 0.3.4

Is GHSA-xffm-g5w8-qvg7 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Affected packages

ecosystem package affected fixed in
npm @eslint/plugin-kit
<0.3.4
0.3.4

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of eslint/rewrite published their own advisory on GitHub. Reviewed sources take precedence over it.