Software packages (namely openssl, sshd, dropbear and openvpn) build for LEAF Bering-uClibc are not affected by the recently found Debian OpenSSL vulnerability. So keys generated on a LEAF Bering-uClibc router are secure. Anyway, a Bering-uClibc router can be compromised, if you use keys build on one of the insecure systems (Debian, Ubuntu, etc), e.g. to login via ssh and authorized keys. So please doublecheck your router(s) and replace any vulnerable keys and certificates.