GHSA-w3w9-vrf5-8mx8
MEDIUMGHSA-w3w9-vrf5-8mx8 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in react/http. O3 Security confirms whether GHSA-w3w9-vrf5-8mx8 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
ReactPHP's HTTP server parses encoded cookie names so malicious `__Host-` and `__Secure-` cookies can be sent
Blast Radius
react/httpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
In ReactPHP's HTTP server component versions below v1.7.0, when ReactPHP is processing incoming HTTP cookie values, the cookie names are url-decoded. This may lead to cookies with prefixes like __Host- and __Secure- confused with cookies that decode to such prefix, thus leading to an attacker being able to forge cookie which is supposed to be secure. See also CVE-2020-7070 and CVE-2020-8184 for more information.
Patches
- https://github.com/reactphp/http/commit/663c9a3b77b71463fa7fcb76a6676ffd16979dd6 - Fixed in reactphp/http
v1.7.0
Workarounds
Infrastructure or DevOps can place a reverse proxy in front of the ReactPHP HTTP server to filter out any unexpected Cookie request headers.
References
- CVE-2020-7070, https://bugs.php.net/bug.php?id=79699 and https://github.com/php/php-src/commit/6559fe912661ca5ce5f0eeeb591d928451428ed0
- CVE-2020-8184, https://hackerone.com/reports/895727 and https://github.com/rack/rack/commit/1f5763de6a9fe515ff84992b343d63c88104654c
- Originally introduced via https://github.com/reactphp/http/pull/175
Credits
- Thanks to Marco Squarcina (TU Wien) for reporting this and working with us to coordinate this security advisory
For more information
If you have any questions or comments about this advisory:
- Join the discussion
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | react/http | ≥ 0.7.0&&< 1.7.0 | 1.7.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react/http. 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 react/http to 1.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w3w9-vrf5-8mx8 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-w3w9-vrf5-8mx8 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-w3w9-vrf5-8mx8. 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-w3w9-vrf5-8mx8 in your dependencies?
O3 detects GHSA-w3w9-vrf5-8mx8 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.