The new Envoy 1.13.1 fixes four security issues:
https://www.envoyproxy.io/docs/envoy/v1.13.1/intro/version_history
It's not yet clear whether they affect the 1.12 release we're running, but seems likely:
CVE-2020-8664:
A vulnerability was found in Envoy, where using SDS with Combined Validation Context Using the same secret (e.g. trusted CA) across many resources together with the combined validation context could lead to the “static” part of the validation context to be not applied, even though it was visible in the active config dump.
CVE-2020-8661:
A vulnerability was found in Envoy version 1.13.0 or earlier may consume excessive amounts of memory when responding internally to pipelined requests.
CVE-2020-8660:
A vulnerability was found in Envoy. where TLS inspector could have been bypassed (not recognized as a TLS client) by a client using only TLS 1.3. Because TLS extensions (SNI, ALPN) were not inspected, those connections might have been matched to a wrong filter chain, possibly bypassing some security restrictions in the process.
CVE-2020-8659:
A vulnerability was found in Envoy version 1.13.0 or earlier may consume excessive amounts of memory when proxying HTTP/1.1 requests or responses with many small (i.e. 1 byte) chunks.