CVE-2019-5307 in P30
Summary
by MITRE
Some Huawei 4G LTE devices, P30 versions before ELE-AL00 9.1.0.162(C01E160R1P12/C01E160R2P1) and P30 Pro versions before VOG-AL00 9.1.0.162(C01E160R1P12/C01E160R2P1), are exposed to a message replay vulnerability. For the sake of better compatibility, these devices implement a less strict check on the NAS message sequence number (SN), specifically NAS COUNT. As a result, an attacker can construct a rogue base station and replay the GUTI reallocation command message in certain conditions to tamper with GUTIs, or replay the Identity request message to obtain IMSIs. (Vulnerability ID: HWPSIRT-2019-04107)
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Analysis
by VulDB Data Team • 09/28/2023
The vulnerability CVE-2019-5307 affects Huawei 4G LTE devices including P30 and P30 Pro models with specific software versions, representing a critical security flaw in the network access security mechanisms of these mobile devices. This vulnerability stems from insufficient validation of NAS (Network Access Service) message sequence numbers, specifically the NAS COUNT field that should maintain strict sequential ordering to prevent message replay attacks. The issue manifests in devices where Huawei implemented relaxed security checks for compatibility reasons, creating a window of opportunity for attackers to exploit the system's trust in message ordering. The vulnerability is particularly concerning as it undermines fundamental security protocols that protect mobile device identity and network access integrity.
The technical flaw resides in the improper implementation of NAS COUNT validation within the LTE protocol stack of affected Huawei devices. The NAS COUNT field serves as a critical sequence number that ensures messages are processed in proper chronological order and prevents replay attacks by maintaining strict monotonically increasing values. However, these devices implement a less strict validation mechanism that allows certain sequence number values to be accepted even when they might indicate replayed or tampered messages. This weakness enables attackers to construct malicious rogue base stations that can intercept legitimate network communications and replay specific NAS messages with modified sequence numbers. The vulnerability specifically impacts the GUTI (Globally Unique Temporary Identifier) reallocation command messages and Identity request messages, which are fundamental components of LTE network authentication and identification processes.
The operational impact of this vulnerability extends beyond simple privacy concerns to potentially enable sophisticated attacks on mobile network security. An attacker positioned within range of an affected device can exploit this weakness to manipulate GUTI values, effectively allowing them to impersonate legitimate network communications or track device movements across different network segments. The ability to replay Identity request messages provides access to IMSI (International Mobile Subscriber Identity) values, which serve as unique identifiers for mobile subscribers and are crucial for network authentication and subscriber management. This vulnerability creates a pathway for attackers to perform location tracking, subscriber identification, and potentially unauthorized network access, representing a significant threat to mobile network security and user privacy. The impact is particularly severe given that these devices operate in public network environments where such attacks can be conducted without requiring physical access to the target device.
Mitigation strategies for CVE-2019-5307 should focus on both immediate device updates and network-level protective measures. Huawei has released firmware updates addressing this vulnerability, and users should immediately apply the available security patches to affected P30 and P30 Pro devices. Network operators should implement monitoring solutions to detect anomalous NAS message patterns that might indicate replay attacks, particularly focusing on unusual GUTI reallocation sequences or repeated Identity request messages. The vulnerability aligns with CWE-310 (Cryptographic Issues) and CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) as it involves weak cryptographic validation mechanisms and improper sequence number handling. From an ATT&CK framework perspective, this vulnerability maps to T1566 (Phishing with Social Engineering) and T1071.004 (Application Layer Protocol: DNS) as attackers could leverage this weakness to conduct more sophisticated attacks. Organizations should also consider implementing network segmentation and enhanced monitoring of NAS message flows to detect potential exploitation attempts. The vulnerability demonstrates the importance of maintaining strong cryptographic validation even when compatibility considerations might suggest relaxed security measures, as the potential impact of such weaknesses can extend far beyond their apparent scope.