Executive brief
FlexRIC, a controller used in Open RAN cellular networks to manage radio resources, is vulnerable to a remote crash. An attacker can cause the controller to shut down by initiating and then immediately closing a network connection before the standard setup process completes. This results in a denial of service, disconnecting cellular base stations and disrupting network operations.
Technical details
A reachable assertion (CWE-617) exists in the FlexRIC near-RT RIC component within the SCTP shutdown notification handler. The vulnerability is located in src/ric/not_handler_ric.c in the notification_handle_ric() function. The software assumes a mapping between an SCTP association and an E2 node always exists during the cleanup path and enforces this via an assert() statement. A remote, unauthenticated attacker can trigger this assertion by completing an SCTP handshake on port 36421 and immediately disconnecting without sending any E2AP messages. This causes the RIC process to abort, leading to a denial of service for all connected E2 nodes and xApps.
Affected products
- EURECOM FlexRIC v2.0.0 through commit 6a595d8b
Timeline
- 2026-06-01: disclosed
- 2026-06-01: advisory