CVE-2022-25745 in 9205 LTE Modem
Summary
by MITRE • 04/13/2023
Memory corruption in modem due to improper input validation while handling the incoming CoAP message
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Analysis
by VulDB Data Team • 04/13/2023
The vulnerability identified as CVE-2022-25745 represents a critical memory corruption issue within modem firmware that arises from inadequate input validation during the processing of incoming Constrained Application Protocol messages. This flaw exists at the intersection of network protocol handling and memory management, creating a pathway for malicious actors to potentially execute arbitrary code or cause system instability. The CoAP protocol, designed for resource-constrained devices in internet of things environments, introduces specific parsing complexities that when mishandled can lead to buffer overflows or other memory corruption conditions. The vulnerability specifically manifests when the modem receives malformed CoAP messages that exceed expected parameter boundaries or contain unexpected data structures, triggering improper memory allocation or manipulation routines within the firmware's network processing stack.
The technical implementation of this vulnerability stems from insufficient validation mechanisms that should have been implemented to sanitize incoming CoAP message parameters before processing. When a modem receives a CoAP message, it typically parses the message header and payload to determine appropriate handling procedures, but the lack of proper boundary checks and input sanitization allows attackers to craft malicious payloads that can overwrite adjacent memory locations. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The memory corruption can manifest through various attack vectors including malformed CoAP options, unexpected payload lengths, or crafted message sequences that exploit the modem's parsing logic. The underlying architecture of modem firmware often involves complex state machines and protocol handlers that may not adequately account for all possible input variations, particularly when dealing with the variable-length nature of CoAP messages and their option encoding schemes.
From an operational perspective, this vulnerability presents significant risks to network infrastructure and connected devices that rely on modem functionality for communication. Attackers could leverage this weakness to disrupt service availability through denial-of-service conditions or potentially gain unauthorized access to modem management interfaces. The impact extends beyond individual device compromise to potentially affect entire network segments if the vulnerability exists across multiple modem implementations from the same vendor or firmware version. Network operators and device manufacturers face increased risk of unauthorized access to critical communication infrastructure, particularly in scenarios where modems serve as gateways for industrial control systems, smart grid communications, or mobile network backhaul connections. The vulnerability's exploitation potential aligns with ATT&CK technique T1059, which covers command and script injection, and T1499, covering endpoint disruption through resource consumption or system instability.
Mitigation strategies for CVE-2022-25745 should prioritize immediate firmware updates from affected vendors, which typically include input validation patches, memory boundary checks, and improved error handling routines for CoAP message processing. Network segmentation and monitoring solutions should be implemented to detect anomalous CoAP traffic patterns that might indicate exploitation attempts, while also implementing proper access controls and authentication mechanisms for modem management interfaces. Security professionals should conduct thorough vulnerability assessments of modem deployments, particularly focusing on devices that handle untrusted network traffic or serve as critical communication links in industrial environments. The remediation process should also include network traffic analysis to identify potential exploitation attempts and establish baseline behavior for normal CoAP message handling to facilitate detection of anomalous patterns. Organizations should consider implementing network-based intrusion detection systems specifically tuned to detect malformed CoAP messages and other indicators of compromise related to this vulnerability class, while also ensuring proper patch management procedures are in place to address similar issues in other network protocol implementations.