Security tools report the default SSL Ciphers are too weak
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The content on this page relates to platforms which are not supported. Consequently, Atlassian Support cannot guarantee providing any support for it. Please be aware that this material is provided for your information only and using it is done so at your own risk.
Security and penetration tests of an Atlassian product server (or other applications using Apache Tomcat) may report that some weak SSL ciphers are enabled. Here's an example:
The weak SSL ciphers enabled EXP-RC4-MD5, EDH-RSA-DES-CBC-SHA EXP-EDH-RSA-DESCBC-SHA DES-CBC-SHA EXP-DES-CBC-SHA TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
The standalone version of Tomcat has SSL Ciphers enabled that may not comply with high-security standards. Pre-existing Tomcat containers (for use with the WAR distribution) may also have these weak ciphers enabled.
The best way to solve this issue is to configure Java to use a Diffie-Hellman 2048 bit-group as documented at Logjam (CVE-2015-4000) and Atlassian Products. This workaround is available for Java version 8 and above so long as your Atlassian applications are compatible with it.
Please note Java versions before 8 cannot use a Diffie-Hellman key size above 1024bits so make sure to upgrade all application linked products to use Java 8 before increasing the Diffie-Hellman key size above 1024bits.
Specifically set the following ciphers by adding the following code block in the SSL Connector section to:
$CONFLUENCE_INSTALL/conf/server.xmlfile in the case of Confluence.
apache-tomcat/conf/server.xmlfile in the case of Crowd.
$JIRA_INSTALL/conf/server.xmlfile in the case of JIRA.
$BITBUCKETSERVER_HOME/shared/server.xmlin the case of Bitbucket Server 4.x.
useCipherSuitesOrder="true" useServerCipherSuitesOrder="true" ciphers="TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_256_GCM_SHA384, TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA"
For Bitbucket Server 5.0+, the ciphers can be controlled by adding
$BITBUCKET_HOME/shared/bitbucket.properties with the ciphers from above.
Note: these ciphers come from the Mozilla SSL Configuration Generator at the intermediate level converted to their respective IANA names and with DES-CBC3-SHA removed (Java doesn't support it at the current time). With the above ciphers setting old clients such as Windows XP and Java 6 will not be able to connect.
|Application||Using SSL with your application|
|Running JIRA applications over SSL or HTTPS|
|Confluence||Running Confluence over SSL or HTTPS|
(previously called Stash)
|Fisheye / Crucible||Fisheye SSL Configuration (terminating at Tomcat)|