CVE-2022-20083 in MT2731
Summary
by MITRE • 07/06/2022
In Modem 2G/3G CC, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution when decoding combined FACILITY with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY00803883; Issue ID: MOLY00803883.
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Analysis
by VulDB Data Team • 07/19/2022
The vulnerability identified as CVE-2022-20083 resides within the Modem 2G/3G Call Control component, specifically affecting the decoding process of combined FACILITY messages. This flaw represents a critical security weakness that could enable remote code execution without requiring any user interaction or additional privileges. The vulnerability manifests as an out-of-bounds write condition that occurs when the modem fails to properly validate input data during the processing of FACILITY messages, which are essential components in telephony signaling protocols. Such a condition typically arises when a program writes data beyond the allocated memory boundaries, potentially overwriting adjacent memory locations that could contain critical program data or execution instructions.
The technical implementation of this vulnerability stems from the absence of proper bounds checking mechanisms within the modem's signal processing code. When a combined FACILITY message is received and processed, the system does not validate the length or boundaries of the incoming data before attempting to write it to memory. This missing validation creates an opportunity for attackers to craft malicious FACILITY messages that, when processed by the vulnerable modem, trigger the out-of-bounds write condition. The lack of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited remotely through network-based attacks without any need for physical access or user engagement.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides a pathway for remote code execution within the modem's operating environment. Attackers who successfully exploit this vulnerability could potentially gain control over the modem's execution flow, allowing them to execute arbitrary code with the privileges of the modem process. This could lead to complete compromise of the device's communication capabilities, enabling man-in-the-middle attacks, data interception, or even broader network infiltration through the compromised modem. The vulnerability affects 2G/3G modem implementations, making it particularly concerning given the continued deployment of legacy cellular infrastructure in various critical applications.
Security practitioners should consider this vulnerability in relation to CWE-129, which specifically addresses insufficient bounds checking, and the broader ATT&CK framework's techniques for privilege escalation and remote code execution. The patch ID MOLY00803883 indicates that this issue has been addressed through firmware updates, emphasizing the importance of timely security patch management for cellular modem components. Organizations should prioritize immediate deployment of the vendor-provided patch while also implementing network monitoring to detect potential exploitation attempts. The vulnerability's remote exploitability without user interaction makes it a high-priority concern for network security teams responsible for protecting cellular infrastructure and mobile communication systems.