CyRC Vulnerability Advisory: CVE-2023-23846 Denial-of-Service Vulnerability in Open5GS GTP Library

INDUSTRY.co.id - Singapore- The Synopsys Cybersecurity Research Center (CyRC) has exposed CVE-2023-23846, a vulnerability in Open5GS. Open5GS is a C-language open source implementation that provides both 4G/LTE enhanced packet core (EPC) and 5G functionalities for mobile network deployments with an AGPLv2 or commercial license.

It is primarily used to build and deploy private LTE/5G telecom network core functions by researchers and commercial entities such as telecom network operators.

Due to insufficient length validation in the Open5GS GTP library when parsing extension headers in GPRS tunneling protocol (GPTv1-U) messages, a protocol payload with any extension header length set to zero causes an infinite loop. The affected process becomes immediately unresponsive, resulting in denial of service and excessive resource consumption.

Because the code resides in a common GTP library that is shared across different functions, this vulnerability is effectively present in all deployed endpoints configured to accept and handle GTP-U messages, including the 5G user plane function (UPF, provided by open5gs-upfd), the 5G session management function (SMF, provided by open5gs-smfd), and the LTE/EPC serving gateway user plane function (SGW-U, provided by open5gs-sgwud).