Public bug reported: While securing our boxes, I noticed that testssl was flagging the absence of server cipher order:
./testssl.sh localhost:636 Has server cipher order? nope (NOT ok) While trying to set it using the following command, slapd just crashed: dapmodify -Y EXTERNAL -H ldapi:/// <<'EOF' dn: cn=config changetype: modify replace: olcTLSCipherSuite olcTLSCipherSuite: SECURE:-VERS-SSL3.0:-3DES-CBC:-ARCFOUR-128:%SERVER_PRECEDENCE - EOF Without the %SERVER_PRECEDENCE, it works. According to https://gnutls.org/manual/html_node/Priority-Strings.html and http://blog.lighttpd.net/articles/2013/06/01/mitigating-beast-with- gnutls/ this is indeed the proper setting to add server cipher order. Same issue happens with %FALLBACK_SCSV ("Downgrade attack prevention NOT supported"). There seems to be no setting to fix "Secure Client- Initiated Renegotiation". However, adding %SAFE_RENEGOTIATION (although not fixing anything) at least doesn't crash slapd 1) root@xl:~# lsb_release -rd Description: Ubuntu 14.04.4 LTS Release: 14.04 2) root@xl:~# apt-cache policy slapd slapd: Installed: 2.4.31-1+nmu2ubuntu8.2 Candidate: 2.4.31-1+nmu2ubuntu8.2 Version table: *** 2.4.31-1+nmu2ubuntu8.2 0 500 http://be.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages 100 /var/lib/dpkg/status 2.4.31-1+nmu2ubuntu8 0 500 http://be.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages 3) What I expected to happen: There should be a a way to enforce server cipher order in slapd, as well as protect against Client-Initiated Renegotiation and prevent downgrade attacks 4) What happened instead When trying to enable these settings that would make slapd more secure, it crashes (and after restart, the requested settings are still not enabled) ** Affects: openldap (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1591681 Title: Impossible to configure GnuTLS' %SERVER_PRECEDENCE setting in slapd To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openldap/+bug/1591681/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
