CWE-295

The httplib and urllib Python libraries that Splunk shipped with Splunk Enterprise did not validate certificates using the certificate authority (CA) certificate stores by default in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203. Python 3 client libraries now verify server certificates by default and use the appropriate CA certificate stores for each library. Apps and add-ons that include their own HTTP libraries are not affected. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

Splunk Enterprise peers in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203 did not validate the TLS certificates during Splunk-to-Splunk communications by default. Splunk peer communications configured properly with valid certificates were not vulnerable. However, an attacker with administrator credentials could add a peer without a valid certificate and connections from misconfigured nodes without valid certificates did not fail by default. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

Splunk Enterprise peers in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203 did not validate the TLS certificates during Splunk-to-Splunk communications by default. Splunk peer communications configured properly with valid certificates were not vulnerable. However, an attacker with administrator credentials could add a peer without a valid certificate and connections from misconfigured nodes without valid certificates did not fail by default. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

In Splunk Enterprise and Universal Forwarder versions before 9.0, the Splunk command-line interface (CLI) did not validate TLS certificates while connecting to a remote Splunk platform instance by default. After updating to version 9.0, see Configure TLS host name validation for the Splunk CLI https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation#Configure_TLS_host_name_validation_for_the_Splunk_CLI to enable the remediation. The vulnerability does not affect the Splunk Cloud Platform. At the time of publishing, we have no evidence of exploitation of this vulnerability by external parties. The issue requires conditions beyond the control of a potential bad actor such as a machine-in-the-middle attack. Hence, Splunk rates the complexity of the attack as High.

`Undici.ProxyAgent` never verifies the remote server’s certificate, and always exposes all request & response data to the proxy. This unexpectedly means that proxies can MitM all HTTPS traffic, and if the proxy’s URL is HTTP then it also means that nominally HTTPS requests are actually sent via plain-text HTTP between Undici and the proxy server.

Starting with diego-release 2.55.0 and up to 2.69.0, and starting with CF Deployment 17.1 and up to 23.2.0, apps are accessible via another port on diego cells, allowing application ingress without a client certificate. If mTLS route integrity is enabled AND unproxied ports are turned off, then an attacker could connect to an application that should be only reachable via mTLS, without presenting a client certificate.