cbcvebase.
CVE-2020-10770
published 2020-12-15

CVE-2020-10770: A flaw was found in Keycloak before 13.0.0, where it is possible to force the server to call out an unverified URL using the OIDC parameter request_uri. This…

PriorityP276medium5.3CVSS 3.1
AVNACLPRNUINSUCNILAN
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
69.72%
99.3th percentile
A flaw was found in Keycloak before 13.0.0, where it is possible to force the server to call out an unverified URL using the OIDC parameter request_uri. This flaw allows an attacker to use this parameter to execute a Server-side request forgery (SSRF) attack.

Affected

3 ranges
VendorProductVersion rangeFixed in
debianlemonldap-ng< lemonldap-ng 2.16.1+ds-deb12u2 (bookworm)lemonldap-ng 2.16.1+ds-deb12u2 (bookworm)
lemonldap-nglemonldap< 2.17.12.17.1
redhatkeycloak< 12.0.212.0.2

Detection & IOCsextracted from sources · hover to see the quote

url/auth/realms/master/protocol/openid-connect/auth?scope=openid&response_type=code&redirect_uri=valid&state=cfx&nonce=cfx&client_id=security-admin-console&request_uri=http://{{interactsh-url}}/
path/auth/realms/master/protocol/openid-connect/auth
  • Monitor for outbound HTTP requests triggered by the OIDC `request_uri` parameter in Keycloak's OpenID Connect auth endpoint; an unauthenticated GET to `/auth/realms/master/protocol/openid-connect/auth` with a `request_uri` pointing to an external/internal host is the attack pattern.
  • Shodan/FOFA fingerprinting for exposed Keycloak instances: search for `http.html:"keycloak"`, `http.title:"keycloak"`, or favicon hash `-1105083093` to identify attack surface.
  • The Nuclei template matcher confirms exploitation by checking for an HTTP interaction on the interactsh protocol, meaning any HTTP callback to the OOB URL confirms the server fetched the attacker-supplied `request_uri`.
  • ·The vulnerability is exploitable only when the default client configuration for `security-admin-console` is present and the `request_uri` OIDC parameter is not restricted; fixed in Keycloak 13.0.0+.
  • ·The exploit is unauthenticated — no credentials are required to trigger the SSRF via the public OpenID Connect authorization endpoint.

CVSS provenance

nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:P/A:N
osv5.3MEDIUM
vulncheck5.3MEDIUM
vendor_debian5.3MEDIUM
vendor_redhat5.3MEDIUM
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