Jiadai Wang

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** The iApp message dispatcher contains a reachable assertion. The dispatcher uses the `assert()` function to validate incoming E2AP messages against a 9-entry whitelist. A remote unauthenticated attacker can send a decodable E2AP PDU with a message type not present in the whitelist, triggering a SIGABRT (a signal sent to a process to force it to abort) and crashing the iApp process on port 36422. Because iApp and the near-RT RIC share a single process, this action terminates the entire RIC service, resulting in the disconnection of all xApps and E2 Nodes. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** The iApp process on port 36421 crashes when it receives a duplicate E2 SETUP REQUEST from the same or a spoofed E2 Node. This occurs because the iApp registry uses an `assert()` function to enforce node ID uniqueness instead of implementing a controlled rejection. A remote unauthenticated attacker can trigger a SIGABRT (a signal sent to a process to force it to abort) by sending two E2 SETUP REQUESTs with identical E2 node configurations. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** A validation mismatch between layers allows a remote unauthenticated attacker to crash the iApp process on port 36422 via SIGABRT. The issue occurs when the iApp receives an 'E42 RIC SUBSCRIPTION REQUEST' containing an empty `ricEventTriggerDefinition` field; while the E42 layer decoder accepts the empty field as valid, the E2AP encoder enforces a non-empty constraint when forwarding the request, leading to the crash. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** The near-RT RIC contains reachable `assert(0)` calls within stub message handlers for E2AP message types that are whitelisted but not yet implemented. A remote unauthenticated attacker can cause the near-RT RIC process on port 36421 to crash via SIGABRT by sending a decodable E2AP PDU of an unimplemented type, such as `E2nodeConfigurationUpdate`. The message successfully passes whitelist validation but triggers an unconditional assertion in the handler. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** A reachable assertion in the `e2ap create pdu()` function is triggered when ASN.1 PER (Packed Encoding Rules, a binary encoding format for ASN.1 data) decoding fails. A remote unauthenticated attacker can send a non-PER byte sequence over SCTP to the near-RT RIC on port 36421 or the iApp on port 36422, causing the process to crash via SIGABRT. This occurs before any protocol-level validation takes place and affects E2AP protocol versions v1.01, v2.03, and v3.01. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** An issue exists where a `uint16 t` counter is used for `xapp id` assignment but is stored in `uint32 t` message fields. After more than 65,530 E42 SETUP REQUESTs, the 16-bit counter wraps around, resulting in duplicate `xapp ids`. This causes the iApp (port 36422) to crash when it attempts to register a duplicate ID within its internal data structure. A remote attacker can trigger this crash by repeatedly connecting and requesting new xApp registrations. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** FlexRIC version 2.0.0 **Description** An issue exists where the software trusts the `xapp id` field from E42 message payloads without binding it to the sender's SCTP association. The validation function `valid xapp id()` only verifies that the value is within the assigned range. A remote unauthenticated attacker can impersonate any xApp by specifying a target `xapp id` in requests sent to the iApp endpoint on port 36422. This leads to responses being misrouted to the victim xApp, which can cause the victim xApp, the RIC, or the iApp to crash due to state inconsistencies in the red-black tree data structure, a self-balancing binary search tree used for efficient data storage and retrieval. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.