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Protection Mechanism Failure

CVE-2025-64763

Medium
5.3/10

Summary

Envoy is a high-performance edge/middle/service proxy. In versions through 1.33.12, 1.34.x through 1.34.10, 1.35.x through 1.35.6, and 1.36.x through 1.36.2, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The "envoy.reloadable_features.reject_early_connect_data" runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.

  • LOW
  • NETWORK
  • NONE
  • UNCHANGED
  • NONE
  • NONE
  • LOW
  • NONE

CWE-693 - Protection Mechanism Failure

The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.

References

Advisory Timeline

  • Published