This article applies as of PRTG 24

PRTG Network Monitor security features

We at Paessler take the responsibility for your network safety seriously. We put a lot of effort into providing you with the most secure network monitoring solution possible. A strong focus is especially on the secure connections to and from the PRTG web server. However, PRTG also includes many other security mechanisms to protect against potential attacks.

The list below shows you sample security features of PRTG:

• The PRTG web server supports SSL encryption (HTTPS, TLS, Elliptic Curve Cryptography, Forward Secrecy) with OpenSSL libraries of the 3.0.x branch.
  
  Note: OpenSSL 1.1.1t is deprecated. OpenSSL 3.0.x does not support certificates signed with SHA1 or older. The minimum recommended hash strength is SHA256. This can cause issues in PRTG, such as PRTG services failing to start when using self-signed certificates. Use updated TLS certificates to avoid such issues. Read more about changes caused by the update to OpenSSL 3.0.x here.
• PRTG only accepts the most secure ciphers for SSL/TLS connections. These ciphers have to allow Perfect Forward Secrecy and TLS 1.3. See below for used ciphers.
• PRTG does not support SSL v3 or cryptographically broken ciphers (MD5, DES, RC4) for outgoing connections. Note: HTTP sensors that do not offer any ciphers supported by OpenSSL 1.1.1 show the error ssl3_read_bytes:sslv3 alert handshake failure.
• All communication between probe(s), PRTG core server(s), and clients is secured via SSL encryption. The same goes for cluster probe connections. For more information about how PRTG uses SSL, see this article.
• PRTG uses an RSA certificate with 2048 bits as the default certificate.
• PRTG uses uniquely generated Diffie-Hellman (DH) parameters with a 1024-bit key by default. Note: You can also change the key length manually. See this article for details.
• You can filter probe connections to the PRTG core server. This means that you are able to allow connections from specific IP addresses only or deny connections from certain IP addresses (or even from all). A remote probe or mini probe must also have a special access key to connect.
• The PRTG web server cleans and sanitizes all GET and POST parameters that could potentially be used for cross-site scripting (XSS) attacks.
• PRTG replaces angle brackets (<>) with braces ({}) in Name fields to prevent XSS attacks.
• The PRTG System Administrator user can give individual access rights to each user account and to each user group. By default, users do not have permissions to see or change anything in the PRTG web interface without the explicit rights provided by the administrator.
• The PRTG web server does not deliver files from folders that are not configured by PRTG. This feature helps to avoid directory traversal attacks.
• The internal data management of PRTG is not based on an SQL server, so SQL injection attacks are impossible.
• You cannot edit script files for custom sensors, SQL sensors, and custom notifications within the PRTG web interface, so anyone who wants to edit these scripts must have access to the file system. This prevents users that have access to the PRTG web interface from injecting and running malicious scripts on the PRTG core server system. See this article for more information about this security feature.
• Every user account requires a password.
• A password that you enter into any web page of the PRTG web interface (for example, login credentials for a sensor) will never be sent back to the browser.
• PRTG stores internal passwords encrypted and never in log files. If you send a support bundle to the Paessler support team, passwords are removed from the configuration file in advance by default.
• PRTG logs out users that were inactive for a defined time span.
• PRTG system administrators must reauthenticate with their credentials every 15 minutes while working on administration pages. Both the logout and the reauthentication mechanism help to prevent unauthorized access to PRTG and secure the PRTG web interface against potential phishing attacks.

Other optional security settings include:

• The ability to disable browser auto-complete in the login form
• To deny loading of PRTG web pages in frame elements. This is an additional protection mechanism against clickjacking attacks.
  • Note: PRTG also never allows login forms in frames.

Elliptic curve and ciphers

PRTG uses the secp384r1 elliptic curve and the following ciphers:

High security modus (default):

'ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256!ADH!aNULL!eNULL!LOW!3DES!MD5!EXP!PSK!SRP!DSS!RC4'
https://www.ssllabs.com/ssltest:
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

Weak security modus:

ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AES:RSA+3DES:!ADH:!AECDH:!MD5:!DSS'
https://www.ssllabs.com/ssltest:
TLS_RSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_RSA_WITH_3DES_EDE_CBC_SHA
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

SSH sensors: ciphers, MAC, key xxchange (KEX), key types

The default SSH engine of SSH sensors uses the following ciphers, MAC, KEX, and key types:

Ciphers: aes256-ctr, aes192-ctr, aes128-ctr, aes256-cbc, aes192-cbc, aes128-cbc

MAC: hmac-sha1, none or hmac-sha2-512, hmac-sha2-256, hmac-sha1, none

KEX: [email protected], ecdh-sha2-nistp256, diffie-hellman-group1-sha1, diffie-hellman-group14-sha1

Key types: ssh-dss, ssh-rsa or ssh-ed25519, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, ssh-dss, ssh-rsa