security: fix multiple CVEs

Signed-off-by: Anish Ramasekar <anish.ramasekar@gmail.com>

docker/proxy-init.Dockerfile

@@ -3,7 +3,9 @@ ARG BASEIMAGE=k8s.gcr.io/build-image/debian-iptables:bullseye-v1.5.1
 FROM --platform=${TARGETPLATFORM:-linux/amd64} ${BASEIMAGE}
 
 # upgrading zlib1g due to CVE-2022-37434
-RUN clean-install ca-certificates zlib1g
+# upgrading libc-bin and libc6 due to CVE-2021-3999
+# upgrading libpcre2-8-0 due to CVE-2022-1586, CVE-2022-1587
+RUN clean-install ca-certificates zlib1g libc-bin libc6 libpcre2-8-0
 COPY ./init/init-iptables.sh /bin/
 RUN chmod +x /bin/init-iptables.sh
 # Kubernetes runAsNonRoot requires USER to be numeric