CVE-2022-20375 in Android
Summary
by MITRE • 08/11/2022
In LteRrcNrProAsnDecode of LteRrcNr_Codec.c, there is a possible out of bounds read due to a missing bounds check. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-180956894References: N/A
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Analysis
by VulDB Data Team • 08/11/2022
The vulnerability identified as CVE-2022-20375 resides within the LTE Radio Resource Control Non-standalone (NR) protocol implementation in Android kernel components, specifically within the LteRrcNr_Codec.c source file. This issue manifests in the LteRrcNrProAsnDecode function where a critical bounds check is absent during ASN.1 decoding operations. The flaw represents a classic out-of-bounds read condition that occurs when processing incoming network protocol data, particularly in the context of 5G NR (New Radio) signaling messages. Such vulnerabilities are particularly concerning in mobile network protocol implementations as they can be exploited by malicious actors to disrupt normal network operations without requiring any special privileges or user interaction.
The technical nature of this vulnerability places it firmly within the CWE-129 category of "Improper Validation of Array Index" and aligns with ATT&CK technique T1059.007 for execution through system commands. The missing bounds check in the ASN.1 decoding process allows an attacker to craft specially malformed network messages that, when processed by the vulnerable Android kernel component, trigger memory access violations. This particular implementation flaw occurs during the decoding phase of network protocol messages, where the system attempts to read data from memory locations beyond the allocated buffer boundaries. The absence of proper validation means that an attacker can manipulate the input data stream to cause the decoder to access memory regions that are not properly allocated for the current operation, leading to unpredictable behavior.
The operational impact of CVE-2022-20375 extends beyond simple denial of service to potentially compromise the stability and reliability of mobile network connections. Since the vulnerability exists in the Android kernel level implementation, any device running affected Android versions becomes susceptible to this attack vector, affecting not just individual users but entire network infrastructure components. The remote exploitation capability means that adversaries can target devices without requiring physical access or user interaction, making it particularly dangerous in mobile environments where devices are constantly communicating with network infrastructure. This vulnerability affects the core protocol handling mechanisms that govern how mobile devices process 5G network signaling information, potentially allowing attackers to disrupt network connectivity, cause device crashes, or create conditions that could be leveraged for more sophisticated attacks. The lack of privilege requirements for exploitation makes this vulnerability especially attractive to threat actors seeking to conduct large-scale disruption campaigns.
Mitigation strategies for CVE-2022-20375 should focus on immediate patch deployment through official Android security updates, which typically address the missing bounds check in the ASN.1 decoding function. Organizations should implement network monitoring solutions to detect anomalous signaling traffic patterns that might indicate exploitation attempts, particularly focusing on malformed 5G NR messages. System administrators should also consider implementing network segmentation and traffic filtering rules to limit exposure to potentially malicious network traffic. The vulnerability underscores the importance of robust input validation in security-critical code sections, particularly in protocol implementation layers where untrusted data from external sources must be processed. Regular security audits of kernel-level components and adherence to secure coding practices, including comprehensive bounds checking and input validation, are essential to prevent similar vulnerabilities from emerging in future implementations. Additionally, device manufacturers should implement more rigorous testing procedures for protocol handling code, including fuzzing and boundary condition testing, to identify and remediate such issues before they can be exploited in the field.