CVE-2023-37013 in MME
Summary
by MITRE • 01/22/2025
Open5GS MME versions <= 2.6.4 contains an assertion that can be remotely triggered via a sufficiently large ASN.1 packet over the S1AP interface. An attacker may repeatedly send such an oversized packet to cause the `ogs_sctp_recvmsg` routine to reach an unexpected network state and crash, leading to denial of service.
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Analysis
by VulDB Data Team • 01/24/2025
The vulnerability identified as CVE-2023-37013 affects Open5GS MME components running versions 2.6.4 and earlier, presenting a critical denial of service risk within mobile network infrastructure. This issue manifests through the S1AP interface, which serves as the control plane protocol connecting eNodeB nodes to the MME in 4G LTE networks. The flaw resides in the ASN.1 packet processing mechanism where the system fails to properly validate packet sizes before attempting to process them, creating a scenario where malicious actors can exploit this weakness through crafted oversized packets.
The technical root cause involves an assertion failure within the ogs_sctp_recvmsg routine that handles SCTP message reception. When an attacker sends a sufficiently large ASN.1 packet through the S1AP interface, the system's packet validation logic becomes overwhelmed, causing the routine to enter an unexpected network state that ultimately results in process termination. This assertion-based vulnerability represents a classic example of inadequate input validation that can be exploited to cause system instability. The flaw operates at the network protocol level, specifically targeting the SCTP (Stream Control Transmission Protocol) implementation within the Open5GS framework, making it particularly dangerous for mobile network operators who rely on continuous service availability.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged for sustained denial of service attacks against mobile network infrastructure. Attackers need only send repeated oversized packets to maintain the crash condition, potentially causing extended outages that affect thousands of mobile users simultaneously. The vulnerability affects the core mobility management entity within the LTE network architecture, which is responsible for handling subscriber authentication, tracking, and mobility management functions. This makes the attack particularly severe as it can compromise the fundamental operations of mobile network services, potentially leading to complete network disruption in affected areas.
Mitigation strategies should focus on immediate version upgrades to Open5GS MME versions 2.6.5 or later, which contain the necessary patches to address the assertion failure in packet processing. Network operators should also implement rate limiting and packet size validation at the network perimeter to prevent oversized packets from reaching vulnerable MME components. Additionally, monitoring systems should be enhanced to detect unusual patterns of SCTP message processing failures that could indicate exploitation attempts. The vulnerability aligns with CWE-129, which covers insufficient input validation, and represents a potential ATT&CK technique under T1499.004 for network denial of service attacks. Organizations should also consider implementing network segmentation and intrusion detection systems to identify and block malicious traffic patterns associated with this specific vulnerability.