Istio Fragments in Path May Lead to Authorization Policy Bypass

Impact

Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with #fragment in the path may bypass Istio’s URI path based authorization policies.

Patches

• Istio 1.11.1 and above
• Istio 1.10.4 and above
• Istio 1.9.8 and above

Workarounds

A Lua filter may be written to normalize the path. This is similar to the Path normalization presented in the Security Best Practices guide.

References

More details can be found in the Istio Security Bulletin

For more information

If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com