Article ID: 117470, created on Sep 24, 2013, last review on Apr 23, 2016

  • Applies to:
  • Operations Automation 6.0
  • Operations Automation 5.5
  • Operations Automation 5.4
  • Business Automation 5.5
  • Business Automation 6.0

Introduction

It is necessary to keep security of HTTPS servers adequate to modern threats. Because new breaches and weaknesses in cryptographic algorithms and protocols are constantly discovered. Moreover, default settings of web servers and operating systems not always provide acceptable level of SSL/TLS security. This article aims to provide guidance about how to configure Linux and Windows web servers to provide good level of SSL/TLS security on Odin Automation UI servers.

It is based on SSL/TLS Deployment Best Practices from Qualys SSLLabs.

Scope

This guide contains instructions how to configure SSL/TLS on Odin Automation servers:

  • OSA Branding server

  • BA Application server

  • Online store

  • NG Web Servers

Please use the following KB article to know how to disable SSLv3 on Qmail servers inside OSA infrastructure.

SSL/TLS Weakneses

The table below lists weaknesses which mitigations are addressed by this article.

Weakness Mitigation
Enabled SSLv3 is a weakness because it is broken due to CVE-2014-3566(POODLE attack). Disable SSLv3
Enabled SSLv2 is a weakness because it is broken. Disable SSLv2
Insecure/broken algorithms used in ciphers (RC4) Disable broken ciphers and algorithms
Small entropy ciphers (DES, 3DES)
* The entropy of 128bits for keys is recommended nowadays.
* 96bits entropy can be tolerable, though.
* 3DES/168 has actual entropy of 112bits.
Disable or de-prioritise ciphers
It is better to not disable 3DES/168bits in order to support IE on Windows XP
Anonymous key negotiation protocols (ADH) Rare situation. Specify proper ciphers to use in Apache
CRIME vulnerability (and its successors like TIME, etc) Disable TLS traffic compression
BEAST vulnerability Do nothing on server side
SSL insecure renegotiation (Apache) Check that latest update for used version of Apache is installed
FREAK vulnerabilityinstall updates and/or disable weak ciphers


Testing SSL/TLS Security

It is not necessary that all steps described in this article be applied to all servers. Test your web servers and fix those that actually demonstrate weaknesses or vulnerabilities.
The best and preferred way to assess security of SSL configuration of the web server is to use Qualys SSL Labs' test: https://www.ssllabs.com/ssltest. The mark A denote reasonably good security level. Scores lower than B require appropriate mitigation steps.

Unfortunately, SSL Labs' test cannot be applied to web servers that are not available from Internet. Use TestSSLServer tool for testing ciphers strength and CRIME vulnerability on servers in your lab (requires Java).

Basic test recommendations for "offline" testing:

  • Ensure certificate is up-to-date and issued by trusted authority
  • Ensure SSLv2 is disabled
  • Ensure SSLv3 is disabled too
  • Check RC4 cipher is not used
  • Check DES cipher is not used
  • Check CRIME is mitigated

Examples:

  1. TestSSLServer output for Windows 2008 R2 server with default configuration. The yellow-marked text points out to insecure protocols (SSLv2 and SSLv3) and ciphers (RC4) that should be disabled. It is no longer recommended to mitigate BEAST attack on server side so we do not pay attention to respective vulnerable mark.

    
    Supported versions: SSLv2 SSLv3 TLSv1.0
    Deflate compression: no
    Supported cipher suites (ORDER IS NOT SIGNIFICANT):
      SSLv2
         RC4_128_WITH_MD5
         DES_192_EDE3_CBC_WITH_MD5
      SSLv3
         RSA_WITH_RC4_128_MD5
         RSA_WITH_RC4_128_SHA
         RSA_WITH_3DES_EDE_CBC_SHA
      TLSv1.0
         RSA_WITH_RC4_128_MD5
         RSA_WITH_RC4_128_SHA
         RSA_WITH_3DES_EDE_CBC_SHA
         RSA_WITH_AES_128_CBC_SHA
         RSA_WITH_AES_256_CBC_SHA
         TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
         TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
    .----------------------
    Server certificate(s):
      0c6e6854baa0323d862c3e41787213e6d8e4006a: CN=10.31.104.33, O=Parallels, C=US
    .----------------------
    Minimal encryption strength:     strong encryption (96-bit or more)
    Achievable encryption strength:  strong encryption (96-bit or more)
    BEAST status: vulnerable
    CRIME status: protected
    
  2. Apache on CentOS 5.3 server (OSA 5.5). CRIME is not mitigated.

    
    Supported versions: SSLv3 TLSv1.0
    Deflate compression: YES
    Supported cipher suites (ORDER IS NOT SIGNIFICANT):
    SSLv3
        RSA_WITH_3DES_EDE_CBC_SHA
        DHE_RSA_WITH_3DES_EDE_CBC_SHA
        RSA_WITH_AES_128_CBC_SHA
        DHE_RSA_WITH_AES_128_CBC_SHA
        RSA_WITH_AES_256_CBC_SHA
        DHE_RSA_WITH_AES_256_CBC_SHA
    (TLSv1.0: idem)
    .---------------------
    Server certificate(s):
    d04135719197cefa8f601f2cf3d1ed055df41afd: CN=cp.parallelscloud.com, OU=EssentialSSL, OU=Domain Control Validated
    .----------------------
    Minimal encryption strength:     strong encryption (96-bit or more)
    Achievable encryption strength:  strong encryption (96-bit or more)
    BEAST status: vulnerable
    CRIME status: vulnerable
    

Important note: Even if during initial deployment TestSSLServer was used it is still necessary to run ssltest when a web server become open into Internet. SSL Lab's test provides much more comprehensive checks, including server certificate strength and trustablity, testing for compatibility with different browsers, more known vulnerabilities.

Windows 2008 Mitigations

Windows 2008 R2 allows broken SSLv2, SSLv3 and weak ciphers for server-side SSL/TLS connections by default.

Mitigation steps:

  1. Upload attached fixDisableWeakCiphers.reg file onto web server machine

  2. Double click on it, and allow operating system to update registry

  3. Restart computer

For more information about meanings of registry settings used, see http://support.microsoft.com/kb/245030.

Linux Mitigations

Weak Cipher and Protocols

Apply following steps, when you have encountered SSLv2, SSLv3, RC4, DES, ADH among list of supported protocols and ciphers by a server during testing.

  1. Add (or modify) following mod_ssl options in SSL/TLS configuration of Apache web server

    SSLProtocol all -SSLv2 -SSLv3
    SSLCipherSuite HIGH:!ADH:!RC4:!aNULL:!eNULL:!EXP:!MEDIUM:!LOW:!MD5
    

    Note: In httpd.conf_pem.override and ng_custom.conf options must be inserted in following form:

    <IFMODULE mod_ssl.c>
    SSLProtocol all -SSLv2 -SSLv3
    SSLCipherSuite HIGH:!ADH:!RC4:!aNULL:!eNULL:!EXP:!MEDIUM:!LOW:!MD5
    </IFMODULE>
    

    NG specific configuration:

    Edit config /etc/httpd/conf/httpd.conf (for OSA < 5.5.8, for later - see the table below)

    And set it as below:

    <IfModule ssl_module> 
    Listen 443 
    AddType application/x-x509-ca-cert .crt 
    AddType application/x-pkcs7-crl .crl 
    SSLSessionCache none 
    SSLMutex "file:/etc/httpd/logs/ssl_mutex" 
    
    SSLEngine off 
    
    SSLCipherSuite HIGH:!ADH:!RC4:!aNULL:!eNULL:!EXP:!MEDIUM:!LOW:!MD5 
    NameVirtualHost *:443 
    <VirtualHost *:443> 
        SSLEngine on 
        SSLProxyEngine on 
        SSLPOACertificateStorage on 
        SSLProtocol all -SSLv2 -SSLv3 
        SSLOptions +StdEnvVars 
    </VirtualHost>
     </IfModule>
    
  2. Reload Apache configuration

The table below contains names of proper configuration files and reload commands depending on type of server you work with.

Server type Config file Restart command
OSA Legacy SH /usr/local/pem/etc/apache/httpd.conf_pem.override service pemhttpd reload
OSA SH NG /etc/httpd/conf.d/ng_custom.conf service httpd reload
BA Application Server /etc/httpd/conf.d/ssl.conf service httpd reload
Store /etc/httpd/conf.d/ssl.conf service httpd reload


CRIME Vuln. Mitigation

Here is mitigation steps for CentOS 5, 6 and CloudLinux 6:

  1. Add the line below in Apache init script

    export OPENSSL_NO_DEFAULT_ZLIB=1
    

    Note: In file /etc/init.d/pemhttpd the line should be inserted after interpreter declaration, like here:

    #!/bin/sh
    #
    # pemapache Start/Stop the pemapache PEM service.
    #
    # chkconfig: 2345 80 20
    # description: pemapache is a SWsoft PEM service
    #
    export OPENSSL_NO_DEFAULT_ZLIB=1
    ..
    
  2. Restart Apache service

The table below contains names of proper files and restart commands depending on type of server you work with:

Server type Init file Restart command
OSA Legacy SH /etc/init.d/pemhttpd service pemhttpd restart
OSA SH NG /etc/sysconfig/httpd service httpd restart
BA Application Server /etc/sysconfig/httpd service httpd restart
Store /etc/sysconfig/httpd service httpd restart

Search Words

aa

TLS v1.2 openssl 0.9

TLS 1.2

crime attack

CVE-2016-0800

Billing is not available now.

DROWN attack

ssl

CVE-2016-0703

proftpd cert tls old

CVE-2015-1637

I want to disable SSLv2 and SSLv3 for imap-ssl and pop3-ssl and STARTTLS(submission)

brand

FREAK

'CVE-2014-3566', 'POODLE', 'SSLv3', 'CRIME', 'CRIME vulnerability', 'BEAST vulnerability', 'SSL insecure renegotiation', 'Small entropy ciphers', 'SSL'

Attachments

caea8340e2d186a540518d08602aa065 5356b422f65bdad1c3e9edca5d74a1ae e12cea1d47a3125d335d68e6d4e15e07 5b048d9bddf8048a00aba7e0bdadef37 2554725ed606193dd9bbce21365bed4e 198398b282069eaf2d94a6af87dcb3ff 801221f8cd76fba7300d1e6817c8e08b 92711db0799e8aefe8e51f12dace0496 ac82ce33439a9c1feec4ff4f2f638899 3627d36199b8ff577605df76e2fa222b bb7e9177fb03488961a3ea554120f328 956c448bddc7e1f3585373687602379f 6f1456866eed87488c0f02b298a741c0

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