CVE-2023-38403

An integer overflow flaw was found in the way iperf3 dynamically allocates memory buffers for JSON-formatted messages. A remote attacker could send a specially crafted sequence of bytes on the iperf3 control channel with a specified JSON message length of 0xffffffff to trigger an integer overflow leading the receiving process to abort due to heap corruption. This flaw allows an attacker to use a malicious client to cause a denial of service of an iperf3 server or potentially use a malicious server to cause connecting clients to crash.

The most common usage of iperf3 is temporary and between trusted devices on private networks. Users may be impacted by this vulnerability if they are hosting publicly available iperf3 servers or are connecting to iperf3 servers they do not control or trust.

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.

Do not run iperf3 as a publicly accessible service unless required. If required, restrict availability to the iperf3 server to only allow access from network ranges of trusted clients. Do not connect to iperf3 servers that you do not trust.