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

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