ReactPHP's HTTP server parses encoded cookie names so malicious `__Host-` and `__Secure-` cookies can be sent

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:

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