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.

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.