Ensure 'sslProtocol' is Configured Correctly for Secure Connectors

HighLevel 1Automatedtomcat

Description

The TLSv1.0 and TLSv1.1 protocols should be disabled via the sslProtocol directive. The TLSv1.0 protocol is vulnerable to information disclosure and both protocols lack support for modern cryptographic algorithms including authenticated encryption. The only SSL/TLS protocols which should be allowed are TLSv1.2 and the newer TLSv1.3 protocol. Every Connector with SSLEnabled="true" must set sslProtocol (on the Connector or its SSLHostConfig, also accepting protocols=) to TLSv1.2, TLSv1.3 or TLSv1.2+TLSv1.3. Compliant when no TLS connector exists. Reads $CATALINA_BASE (default /opt/tomcat) and $CATALINA_HOME (default: $CATALINA_BASE); set them for packaged installs (e.g. CATALINA_BASE=/var/lib/tomcat10, CATALINA_HOME=/usr/share/tomcat10). XML comments are ignored.

How it is checked

Audit method: Shell command

shell

B=${CATALINA_BASE:-/opt/tomcat}; H=${CATALINA_HOME:-$B}; O=${TOMCAT_OWNER:-tomcat_admin}; G=${TOMCAT_GROUP:-tomcat}; x(){ [ -r "$1" ] || return 1; awk 'BEGIN{RS="<!--"} NR==1{print;next} {i=index($0,"-->"); if(i) print substr($0,i+3)}' "$1" | tr '\n\t\r' '   ' | tr '<' '\n'; }; s=$(x "$B/conf/server.xml") || exit 1; printf '%s\n' "$s" | awk 'function at(n,  r){if(match($0,"[[:space:]]" n "[[:space:]]*=[[:space:]]*[\"\047][^\"\047]*")){r=substr($0,RSTART,RLENGTH); sub(/^[^=]*=[[:space:]]*./,"",r); return r} return "-unset-"} function fin(){ if(!inc) return; inc=0; if(se){ n=split(pr,t,/[+, ]+/); k=0; for(i=1;i<=n;i++){ if(t[i]=="") continue; k++; if(t[i]!="TLSv1.2" && t[i]!="TLSv1.3") bad=1 } if(k==0) bad=1 } } /^Connector[[:space:]]/{fin(); inc=1; se=(at("SSLEnabled")=="true"); sc=at("scheme"); sx=at("secure"); pr=at("sslProtocol"); if(pr=="-unset-") pr=""; if($0~/\/>[[:space:]]*$/) fin(); next} /^SSLHostConfig[[:space:]]/ && inc {v=at("sslProtocol"); if(v=="-unset-") v=at("protocols"); if(v!="-unset-") pr=pr "," v} /^\/Connector>/{fin()} END{fin(); print bad?"noncompliant":"compliant"}'

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Set <SSLHostConfig sslProtocol="TLS" protocols="TLSv1.2+TLSv1.3"> (or sslProtocol="TLSv1.2+TLSv1.3") on every TLS connector in server.xml. Restart Tomcat afterwards.

Properties

Operating systems: Any
Tags: tomcattls
Reference: CIS Apache Tomcat 10.1 Benchmark v1.0.0 - 6.5 Ensure 'sslProtocol' is Configured Correctly for Secure Connectors

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target tomcat