Istio (1.8.x, 1.9.0-1.9.5 and 1.10.0-1.10.1) contains a remotely exploitable vulnerability where credentials specified in the Gateway and DestinationRule credentialName field can be accessed from different namespaces.

Istio before 1.8.6 and 1.9.x before 1.9.5 contains a remotely exploitable vulnerability where an external client can access unexpected services in the cluster, bypassing authorization checks, when a gateway is configured with AUTO_PASSTHROUGH routing configuration.

Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.

A NULL pointer dereference was found in pkg/proxy/envoy/v2/debug.go getResourceVersion in Istio pilot before 1.5.0-alpha.0. If a particular HTTP GET request is made to the pilot API endpoint, it is possible to cause the Go runtime to panic (resulting in a denial of service to the istio-pilot application).

In Istio 1.5.0 though 1.5.8 and Istio 1.6.0 through 1.6.7, when users specify an AuthorizationPolicy resource with DENY actions using wildcard suffixes (e.g. *-some-suffix) for source principals or namespace fields, callers will never be denied access, bypassing the intended policy.

An incorrect access control flaw was found in the operator, openshift-service-mesh/istio-rhel8-operator all versions through 1.1.3. This flaw allows an attacker with a basic level of access to the cluster to deploy a custom gateway/pod to any namespace, potentially gaining access to privileged service account tokens. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Istio 1.4.x before 1.4.9 and Istio 1.5.x before 1.5.4 contain the following vulnerability when telemetry v2 is enabled: by sending a specially crafted packet, an attacker could trigger a Null Pointer Exception resulting in a Denial of Service. This could be sent to the ingress gateway or a sidecar, triggering a null pointer exception which results in a denial of service. This also affects servicemesh-proxy where a null pointer exception flaw was found in servicemesh-proxy. When running Telemetry v2 (not on by default in version 1.4.x), an attacker could send a specially crafted packet to the ingress gateway or proxy sidecar, triggering a denial of service.

Istio through 1.5.1 and Envoy through 1.14.1 have a data-leak issue. If there is a TCP connection (negotiated with SNI over HTTPS) to *.example.com, a request for a domain concurrently configured explicitly (e.g., abc.example.com) is sent to the server(s) listening behind *.example.com. The outcome should instead be 421 Misdirected Request. Imagine a shared caching forward proxy re-using an HTTP/2 connection for a large subnet with many users. If a victim is interacting with abc.example.com, and a server (for abc.example.com) recycles the TCP connection to the forward proxy, the victim's browser may suddenly start sending sensitive data to a *.example.com server. This occurs because the forward proxy between the victim and the origin server reuses connections (which obeys the specification), but neither Istio nor Envoy corrects this by sending a 421 error. Similarly, this behavior voids the security model browsers have put in place between domains.

An issue was discovered in Istio 1.3 through 1.3.6. Under certain circumstances, it is possible to bypass a specifically configured Mixer policy. Istio-proxy accepts the x-istio-attributes header at ingress that can be used to affect policy decisions when Mixer policy selectively applies to a source equal to ingress. To exploit this vulnerability, someone has to encode a source.uid in this header. This feature is disabled by default in Istio 1.3 and 1.4.

Istio versions 1.2.10 (End of Life) and prior, 1.3 through 1.3.7, and 1.4 through 1.4.3 allows authentication bypass. The Authentication Policy exact-path matching logic can allow unauthorized access to HTTP paths even if they are configured to be only accessed after presenting a valid JWT token. For example, an attacker can add a ? or # character to a URI that would otherwise satisfy an exact-path match.