GHSA-29mw-wpgm-hmr9
MEDIUMRegular Expression Denial of Service (ReDoS) in lodash
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
lodashnpmlodash-esnpmlodash.trimendnpmDescription
All versions of package lodash prior to 4.17.21 are vulnerable to Regular Expression Denial of Service (ReDoS) via the toNumber, trim and trimEnd functions.
Steps to reproduce (provided by reporter Liyuan Chen):
var lo = require('lodash');
function build_blank(n) {
var ret = "1"
for (var i = 0; i < n; i++) {
ret += " "
}
return ret + "1";
}
var s = build_blank(50000) var time0 = Date.now();
lo.trim(s)
var time_cost0 = Date.now() - time0;
console.log("time_cost0: " + time_cost0);
var time1 = Date.now();
lo.toNumber(s) var time_cost1 = Date.now() - time1;
console.log("time_cost1: " + time_cost1);
var time2 = Date.now();
lo.trimEnd(s);
var time_cost2 = Date.now() - time2;
console.log("time_cost2: " + time_cost2);
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | lodash | ≥ 4.0.0&&< 4.17.21 | 4.17.21 |
| 📦npm | lodash-es | ≥ 4.0.0&&< 4.17.21 | 4.17.21 |
| 📦npm | lodash.trimend | ≥ 4.0.0 | No fix |
| 📦npm | lodash.trim | ≥ 4.0.0 | No fix |
| 💎RubyGems | lodash-rails | ≥ 4.0.0&&< 4.17.21 | 4.17.21 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Lodash versions prior to 4.17.21 are vulnerable to Regular Expression De…
Lodash versions prior to 4.17.21 are vulnerable to Regular Expression De…
Lodash versions prior to 4.17.21 are vulnerable to Regular Expression De…
Lodash versions prior to 4.17.21 are vulnerable to Regular Expression De…
Lodash versions prior to 4.17.21 are vulnerable to Regular Expression De…
Lodash versions prior to 4.17.21 are vulnerable to Regular Expression De…
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lodash. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update lodash to 4.17.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-29mw-wpgm-hmr9 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-29mw-wpgm-hmr9 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-29mw-wpgm-hmr9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-29mw-wpgm-hmr9 in your dependencies?
O3 detects GHSA-29mw-wpgm-hmr9 across npm, RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.