Topic: TLS Version 1.0 Protocol Detection: Nessus scan Warning

[Shrinidhi0409]

We are running our Java Application on RHEL 8.5 OS platform. In our Apache's ssl.conf file, we have enabled only TLSv1.2 protocol. And we are not using TLSv1 and TLSv1.1 protocols in our application.

From RHEL, it is confirmed that "The TLS versions TLS 1.0 and TLS 1.1 protocols are disabled in the DEFAULT system-wide cryptographic policy level. "

And from the below command results, it is confirmed that TLS 1.0 and TLS 1.1 is disabled from the Application Side.

[root@test ~]# openssl s_client -connect <IP_ADDRESS>:8443 -tls1
CONNECTED(00000003)
139679030896448:error:1409442E:SSL routines:ssl3_read_bytes:tlsv1 alert protocol version:ssl/record/rec_layer_s3.c:1544:SSL alert number 70
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 104 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1
Cipher : 0000
Session-ID:
Session-ID-ctx:
Master-Key:
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1662128840
Timeout : 7200 (sec)
Verify return code: 0 (ok)
Extended master secret: no

Below is the output of nmap command

[root@test ~]# nmap -sV --script ssl-enum-ciphers -p 8443 <IP_ADDRESS>
Starting Nmap 7.70 ( https://nmap.org ) at 2022-09-02 20:02 IST
mass_dns: warning: Unable to open /etc/resolv.conf. Try using --system-dns or specify valid servers with --dns-servers
mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers
Nmap scan report for XXXXX (IP_ADDRESS)
Host is up (0.00067s latency).

PORT STATE SERVICE VERSION
8443/tcp open ssl/http Apache httpd
|_http-server-header: Apache
| ssl-enum-ciphers:
| TLSv1.2:
| ciphers:
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (secp256r1) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (secp256r1) - A
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (secp256r1) - A
| compressors:
| NULL
| cipher preference: client
|_ least strength: A
MAC Address: 00:50:56:A7:92:7B (VMware)

We have restricted our application strictly to use TLS 1.2 by modifying ssl.conf file as below

SSLProtocol -ALL +TLSv1.2
SSLCipherSuite ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:AES256-CCM:DHE-RSA-AES256-CCM

Can you please let us know why this Warnings/Vulnerability is appearing during Nessus Security runs and also possible solutions to block TLS 1.0 Version.

Thanks and Regards,
Shrinidhi S

[James Blond]

My current working SSL config. https://raw.githubusercontent.com/JBlond/debian_build_apache24/master/ssl.conf

Yes, that includes TLS 1.3

how ever: Your config is fine. If you replace the last parameter with -tls1_2 you will get back the certificate from your server. Not getting it back means that the connection failed.

Also, the Nmap scan shows only TLS 1.2. Everything is fine. That tool shows a false positive.

I would fix "Secure Renegotiation IS NOT supported " That you can see in my config example from GitHub.

[Shrinidhi0409]

Hi

Thank you for the reply.

As per your suggestion we have checked with our Nessus vendor. They have replied like the port 4567 is using TLS 1.0.

In our application we are using port 4567 as TRUSTSTORE_PORT where it is downloading the required certificates for application to run.

Can you please let us know that the port 4567 is restricted only to download certificates or it can be modified to any other ports where it is not using TLS 1.0?

Regards,
Shrinidhi S