Werk #14482: Use proper HMAC for cookie signing
Komponente | Setup | ||
Titel | Use proper HMAC for cookie signing | ||
Datum | 02.08.2022 | ||
Level | Kleine Änderung | ||
Klasse | Sicherheitsfix | ||
Kompatibilität | Inkompatibel - Manuelle Interaktion könnte erforderlich sein | ||
Checkmk versions & editions |
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Previously to this Werk the Session cookies were signed with with calculating a SHA256 hash over username, session id, a serial plus a secret. This could in theory lead to a "partial message collision".
Since we parse the data given in the cookie and test for validity, we are confident that such an attack is not possible. But to be future-proof we switch to proper HMAC for signing the cookie value. This will invalidate all session cookies for a site. Therefore all users have to reauthenticate to retrieve new valid cookies.