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.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16844
Reference (s):
- https://istio.io/latest/news/security/istio-security-2020-009/
- https://github.com/istio/istio/releases