CVE-2023-37022 in MME
Summary
by MITRE • 01/22/2025
Open5GS MME versions <= 2.6.4 contain a reachable assertion in the `UE Context Release Request` packet handler. A packet containing an invalid `MME_UE_S1AP_ID` field causes Open5gs to crash; an attacker may repeatedly send such packets to cause denial of service.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/15/2026
The vulnerability identified as CVE-2023-37022 affects Open5GS MME components running version 2.6.4 and earlier, representing a critical software flaw that undermines system stability and availability. This issue manifests within the packet handling mechanism specifically designed to process UE Context Release Request messages, which are integral to the Evolved Packet Core network architecture for managing user equipment sessions. The flaw stems from inadequate input validation within the MME's packet processing logic, creating a scenario where malformed packets can trigger unexpected program termination.
The technical root cause involves a missing assertion check for the MME_UE_S1AP_ID field within the UE Context Release Request handler. When an attacker crafts a packet containing an invalid MME_UE_S1AP_ID value, the system encounters a condition that violates expected operational parameters, leading to an assertion failure that terminates the MME process. This behavior aligns with CWE-617, which classifies reachable assertions as a vulnerability category where program assertions can be triggered through external input. The flaw represents a classic example of improper input validation that allows attackers to manipulate program flow and cause unintended system behavior.
The operational impact of this vulnerability extends beyond simple service disruption, as it enables persistent denial of service attacks that can severely compromise network availability. An attacker can repeatedly send malformed packets to the affected MME, causing repeated crashes and system restarts that can lead to extended service outages. This attack vector directly maps to ATT&CK technique T1499.004, which involves network denial of service attacks targeting network infrastructure components. The vulnerability affects the core mobility management entity within the 3GPP LTE network architecture, making it particularly dangerous as it impacts the fundamental ability of the network to manage user equipment connections and maintain service continuity.
Mitigation strategies should focus on immediate patch deployment to Open5GS versions 2.6.5 and later, which contain the necessary assertion checks and input validation improvements. Network administrators should implement rate limiting and packet filtering mechanisms to detect and block suspicious UE Context Release Request messages before they reach the vulnerable MME component. Additionally, monitoring systems should be configured to alert on repeated MME crashes or abnormal restart patterns that may indicate ongoing exploitation attempts. The vulnerability demonstrates the importance of robust input validation in network infrastructure components and highlights the need for comprehensive testing of packet handling logic against malformed inputs. Organizations should also consider implementing intrusion detection systems that can identify patterns consistent with this specific attack vector and maintain regular security updates to protect against similar vulnerabilities in network infrastructure software components.