Security tools report the default SSL Ciphers are too weak
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Problem
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 EXP-RC4-MD5, EDH-RSA-DES-CBC-SHA, EXP-EDH-RSA-DESCBC-SHA, DES-CBC-SHA, and EXP-DES-CBC-SHA were enabledThe 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.
Resolution 1
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.
Resolution 2
Specifically set the following ciphers by adding the following code block in the SSL Connector section to:
$CONFLUENCE_INSTALL/conf/server.xmlfile in the case of Confluence.$CROWD_INSTALL/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"
ciphers="TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_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_DSS_WITH_AES_128_GCM_SHA256,
TLS_DHE_DSS_WITH_AES_256_GCM_SHA384,TLS_DHE_RSA_WITH_AES_256_GCM_SHA384,
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
TLS_DHE_DSS_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_256_CBC_SHA256,
TLS_DHE_DSS_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_256_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,
TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA,TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA,
TLS_SRP_SHA_WITH_AES_256_CBC_SHA,TLS_DHE_DSS_WITH_AES_256_CBC_SHA256,
TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA,TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA,
TLS_SRP_SHA_WITH_AES_128_CBC_SHA,TLS_DHE_DSS_WITH_AES_128_CBC_SHA,
TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA,TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA,
TLS_RSA_WITH_CAMELLIA_256_CBC_SHA,TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA,
TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA,TLS_RSA_WITH_CAMELLIA_128_CBC_SHA"For Bitbucket Server 5.0+, the ciphers can be controlled by adding server.ssl.ciphers in $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 |
|---|---|
JIRA applications |
Running JIRA applications over SSL or HTTPS |
| Confluence | Running Confluence over SSL or HTTPS |
| Bamboo | |
Bitbucket Server (previously called Stash) |
Securing Bitbucket Server with SSL (terminating at Tomcat) |
| FishEye / Crucible | FishEye SSL Configuration (terminating at Tomcat) |