GHSA-4992-7rv2-5pvq
MEDIUMUndici has CRLF Injection in undici via `upgrade` option
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
undici📦undiciReal-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
When an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to:
- Inject arbitrary HTTP headers
- Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)
The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters:
// lib/dispatcher/client-h1.js:1121
if (upgrade) {
header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n`
}
Patches
Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.
Workarounds
Sanitize the upgrade option string before passing to undici:
function sanitizeUpgrade(value) {
if (/[\r\n]/.test(value)) {
throw new Error('Invalid upgrade value')
}
return value
}
client.request({
upgrade: sanitizeUpgrade(userInput)
})
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | undici | all versions | 6.24.0 |
| 📦npm | undici | ≥ 7.0.0&&< 7.24.0 | 7.24.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for undici. 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 undici to 6.24.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4992-7rv2-5pvq 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-4992-7rv2-5pvq 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-4992-7rv2-5pvq. 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-4992-7rv2-5pvq in your dependencies?
O3 detects GHSA-4992-7rv2-5pvq across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.