Keycloak-services: keycloak-services: oidc redirect_uri fragment bypass in http parameter pollution check
8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 3.4epss 0.2%
exploitation probability
0.2%top 91% of all CVEs
observed exploitation
nono source reports it
A flaw was found in the keycloak-services component of Keycloak, which handles OpenID Connect (OIDC) authentication flows. The issue occurs because the security check designed to prevent HTTP parameter pollution only inspects the query portion of a redirect URL and ignores the fragment portion. When a client is configured with a wildcard redirect URI, an attacker can use this to inject duplicate security parameters into the login response. If a client application is not configured correctly, it might trust the attacker's injected data instead of the real security information from Keycloak, leading to session fixation or account confusion.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:L/A:N