Modify S6463: Update rule description (#4526)

rules/S6463/python/rule.adoc

@@ -1,8 +1,6 @@
 Allowing unrestricted outbound communications can lead to data leaks.
 
-A restrictive security group is an additional layer of protection that might
-prevent the abuse or exploitation of a resource. For example, it complicates the
-exfiltration of data in the case of a successfully exploited vulnerability.
+When a security group allows all outbound communications, applications or services within the security group can send data to any external IP address or port without restriction. If a resource within the security group becomes compromised, attackers could send malicious traffic or exfiltrate data to external servers. This could happen even if the resource is not directly exposed to the internet, such as in case of a supply chain attack.
 
 When deciding if outgoing connections should be limited, consider that limiting
 the connections results in additional administration and maintenance work.
@@ -18,9 +16,9 @@ There is a risk if you answered yes to any of those questions.
 
 == Recommended Secure Coding Practices
 
-It is recommended to restrict outgoing connections to a set of trusted
-destinations.
+The principles of defence-in-depth and least privilege suggest that outbound connections should be restricted to a set of trusted destinations.
 
+Consider restricting the security group egress rules so that it can only contact specific locations, such as trusted IP address ranges or other security groups. If any resources require unrestricted outbound access, place them in their own security group.
 
 == Sensitive Code Example