CVE-2023-29552

.The Service Location Protocol (SLP) is vulnerable to an attack through UDP

The OpenSLP provides a dynamic configuration mechanism for applications in local area networks, such as printers and file servers. However, SLP is vulnerable to a reflective denial of service amplification attack through UDP on systems connected to the internet. SLP allows an unauthenticated attacker to register new services without limits set by the SLP implementation. By using UDP and spoofing the source address, an attacker can request the service list, creating a Denial of Service on the spoofed address.

To prevent external attackers from accessing the SLP service, disable SLP on all systems running on untrusted networks, such as those directly connected to the internet. Alternatively, to work around this problem, configure firewalls to block or filter traffic on UDP and TCP port 427.

The OpenSLP protocol specification makes it prone to UDP amplification attacks, and the abuse of exposed OpenSLP servers can be used to contribute to Distributed Denial of Service attacks. Due to the protocol implementation, this issue can't be directly fixed.

This issue affects the Server component of the openslp package, which is only shipped on Red Hat Enterprise Linux 7 and 9. RHEL 8 only ships the Client component, that is not affected by this CVE.

The OpenSLP server is not installed and active on any standard RHEL deployments. If you are using the OpenSLP server, Red Hat recommends to do so in a secure and controlled network environment.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.