Executive brief
EURECOM FlexRIC, a controller used in Open RAN cellular networks to manage radio resources, contains a flaw in how it handles connections from external applications (xApps). An attacker can repeatedly register multiple identities over a single connection, and when that connection is closed, the system fails to clean up all the associated data. Over time, this leads to a buildup of "stale" entries that can exhaust system memory or corrupt the controller's state, potentially disrupting cellular network operations.
Technical details
A resource management vulnerability exists in the FlexRIC iApp component due to improper handling of E42_SETUP_REQUEST messages. The function `e2ap_handle_e42_setup_request_iapp` in `msg_handler_iapp.c` fails to verify if an SCTP association already has an assigned xApp identity, allowing a single connection to bind multiple `xapp_id` values. Upon disconnection, the cleanup logic only identifies and removes the first registered `xapp_id`, leaving subsequent IDs and their associated subscription states as stale entries in memory. A remote, unauthenticated attacker can exploit this by sending multiple setup requests over one SCTP connection to port 36422, leading to uncontrolled resource consumption (CWE-400) and potential state corruption. As of the advisory date, no upstream patch is available.
Affected products
- EURECOM FlexRIC v2.0.0 through commit 6a595d8b
Timeline
- 2026-06-01: disclosed
- 2026-06-01: advisory