CVE-2023-46324 in udm
Summary
by MITRE • 10/25/2023
pkg/suci/suci.go in free5GC udm before 1.2.0, when Go before 1.19 is used, allows an Invalid Curve Attack because it may compute a shared secret via an uncompressed public key that has not been validated. An attacker can send arbitrary SUCIs to the UDM, which tries to decrypt them via both its private key and the attacker's public key.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 11/12/2023
The vulnerability CVE-2023-46324 affects the free5GC udm component in versions prior to 1.2.0, specifically when used with Go versions before 1.19. This represents a critical cryptographic flaw that undermines the security of the 5G core network's user identity management system. The issue stems from improper validation of elliptic curve public keys during the key exchange process, creating a pathway for sophisticated attacks that can compromise the confidentiality and integrity of user communications within the network infrastructure.
The technical flaw manifests in the pkg/suci/suci.go module where the system processes Subscriber Identity Module (SUCI) messages without properly validating the uncompressed public keys provided by attackers. This vulnerability enables what is known as an Invalid Curve Attack, a well-documented cryptographic attack that exploits the mathematical properties of elliptic curve cryptography. When an attacker sends a malicious SUCI message containing an invalid public key, the system attempts to compute a shared secret using both its legitimate private key and the attacker's malformed public key, potentially revealing sensitive information about the network's cryptographic operations.
The operational impact of this vulnerability extends beyond simple data exposure, as it provides attackers with potential access to user identity information and communication patterns within the 5G network. According to the CWE (Common Weakness Enumeration) classification, this corresponds to CWE-310, which specifically addresses cryptographic weaknesses in key management and validation processes. The attack vector allows adversaries to manipulate the key exchange process in a way that can reveal information about the private key or enable the calculation of valid shared secrets without proper authorization. This represents a significant threat to the privacy and security of 5G network users, particularly in environments where the udm component handles sensitive subscriber data.
The vulnerability aligns with several ATT&CK (Attack Tree Framework) techniques including T1583.001 (Pre-compromise: Account Access and T1595.001 (Network Reconnaissance) as attackers can use this flaw to gather intelligence about the network's cryptographic implementation. The attack enables unauthorized access to user identity information that could be used for further targeting or exploitation of the network. Organizations using free5GC udm components must understand that this vulnerability creates a persistent threat that can be exploited over time, potentially allowing attackers to establish long-term monitoring capabilities within the network infrastructure.
Mitigation strategies for CVE-2023-46324 require immediate deployment of version 1.2.0 or later of the free5GC udm component, which includes proper validation of public keys during the key exchange process. Additionally, organizations should ensure their Go runtime environment is updated to version 1.19 or higher, as newer versions include enhanced cryptographic validation mechanisms that prevent Invalid Curve Attack exploitation. The implementation of proper key validation procedures should be complemented by network monitoring systems that can detect anomalous SUCI processing patterns and potential attack attempts. Security teams must also review their cryptographic implementations to ensure all elliptic curve operations include proper validation of public keys before any cryptographic computations are performed, following industry standards such as NIST SP 800-56A for key agreement and validation practices.