CVE-2022-24280: Apache Pulsar Proxy target broker address isn't validated

[Lari Hotari <lhotari () apache org>]

Severity: important

Description:

Improper Input Validation vulnerability in Proxy component of Apache Pulsar allows an attacker to make TCP/IP 
connection attempts that originate from the Pulsar Proxy's IP address.

When the Apache Pulsar Proxy component is used, it is possible to attempt to open TCP/IP connections to any IP address 
and port that the Pulsar Proxy can connect to. An attacker could use this as a way for DoS attacks that originate from 
the Pulsar Proxy's IP address.
It hasn’t been detected that the Pulsar Proxy authentication can be bypassed. The attacker will have to have a valid 
token to a properly secured Pulsar Proxy.

This issue affects Apache Pulsar Proxy versions 2.7.0 to 2.7.4; 2.8.0 to 2.8.2; 2.9.0 to 2.9.1; 2.6.4 and earlier.

Mitigation:

To address the issue, upgraded versions of Apache Pulsar Proxy will only allow connections to known broker ports 6650 
and 6651 by default. In addition, it is necessary to limit proxied broker connections further to known broker addresses 
by specifying brokerProxyAllowedHostNames and brokerProxyAllowedIPAddresses Pulsar Proxy settings. In Pulsar Helm chart 
deployments, the setting names should be prefixed with "PULSAR_PREFIX_".

2.7 users should upgrade Pulsar Proxies to 2.7.5 and apply configuration changes.
2.8 users should upgrade Pulsar Proxies to at least 2.8.3 and apply configuration changes.
2.9 users should upgrade Pulsar Proxies to at least 2.9.2 and apply configuration changes.
2.10 users should apply configuration changes.
Any users running the Pulsar Proxy 2.6.4 and earlier should upgrade to one of the above patched versions and apply 
configuration changes.

Credit:

This issue was discovered by Lari Hotari of DataStax.