Weak cipher used with SSL profiles-f5-all
Vendor: f5
OS: all
Description:
Certain ciphers are now considered weak. Indeni will alert if any SSL profiles are set to use them.
Remediation Steps:
User is advised to reconfigure the SSL cipher used in the affected profile.
|1. Follow the knowledge articles listed below for the weak cipher used. Since F5 devices present the attributes in alphabetical order (to the other side), be careful when adding a property.
|2. DES-CBC3 cipher is considered weak (vulnerability SWEET32). See https://support.f5.com/csp/#/article/K13167034
|3. RC4 cipher is considered weak. See https://support.f5.com/csp/#/article/K16864
How does this work?
This alert logs into the F5 and retrieves the cipher strings being used by each profile and scans for weak ciphers.
Why is this important?
Weak ciphers could allow for man in the middle attacks. Administrators would ideally want to keep track of their cipher string configurations in order to protect their clients against known attack vectors.
Without Indeni how would you find this?
Log into the device through SSH. Enter TMSH and issue the command “cd /;list ltm profile client-ssl recursive ciphers renegotiation renegotiate-size” to retrieve a list of all SSL Client profiles and their ciphers. Then for each cipher string, issue the command "tmm --clientciphers ". Example: “tmm --clientciphers ‘!LOW:!SSLv3:!MD5:!RC4:!DHE:!EXPORT:ECDHE+AES-GCM:ECDHE:RSA+AES:RSA+3DES’”
f5-tmsh-list-profile-client-ssl-recursive-ciphers
name: f5-tmsh-list-profile-client-ssl-recursive-ciphers
description: Find usage of weak ciphers
type: monitoring
monitoring_interval: 60 minutes
requires:
vendor: f5
product: load-balancer
shell: bash
comments:
ssl-weak-cipher:
why: |
Weak ciphers could allow for man in the middle attacks. Administrators would ideally want to keep track of their cipher string configurations in order to protect their clients against known attack vectors.
how: |
This alert logs into the F5 and retrieves the cipher strings being used by each profile and scans for weak ciphers.
can-with-snmp: false
can-with-syslog: false
ssl-weak-protocol:
why: |
Weak protocols could enable for man in the middle attacks. Administrators would ideally want to keep track of their cipher string configurations in order to protect their clients against known attack vectors.
how: |
This alert logs into the F5 and retrieves the cipher strings being used by each profile and scans for weak protocols.
can-with-snmp: false
can-with-syslog: false
steps:
- run:
type: SSH
file: tmsh-list-ltm-profile-client-ssl-recursive-ciphers.remote.1.bash
parse:
type: AWK
file: tmsh-list-ltm-profile-client-ssl-recursive-ciphers.parser.1.awk
CrossVendorSslWeakCipherRule
Failed to fetch the data: https://bitbucket.org/indeni/indeni-knowledge/src/master/rules/templatebased/crossvendor/CrossVendorSslWeakCipherRule.scala