CVE-2026-21551 in T8100
Summary
by MITRE • 08/03/2026
In modem, there is a possible improper input validation. This could lead to remote denial of service with no additional execution privileges needed
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Analysis
by VulDB Data Team • 08/03/2026
This vulnerability represents a critical weakness in modem firmware systems where insufficient input validation mechanisms allow malicious actors to exploit the device through remote means without requiring elevated privileges or execution rights. The flaw resides in how the modem processes incoming data streams, particularly when handling malformed or unexpected inputs that should be properly sanitized before further processing. Such improper validation creates an attack surface where adversaries can craft specific payloads designed to overwhelm or destabilize the modem's operational state.
The technical nature of this vulnerability aligns with common weaknesses identified in the CWE database under categories related to input validation failures and improper error handling within network devices. When modems receive data streams that exceed expected parameters or contain unexpected formatting, the lack of proper sanitization allows these inputs to potentially trigger system crashes or operational degradation. This particular weakness enables what cybersecurity frameworks classify as remote denial of service attacks, where attackers can disrupt legitimate network services without needing physical access or administrative credentials.
From an operational perspective, this vulnerability poses significant risks to network infrastructure reliability and service availability. Modems serve as critical gateways for network connectivity, and their compromise through remote denial of service attacks can result in widespread connectivity disruptions affecting multiple users or devices simultaneously. Network administrators may experience cascading failures as compromised modems disrupt data transmission pathways, potentially leading to extended outages that impact business operations and user productivity.
The attack vector operates entirely through remote communication channels without requiring any elevated privileges, making it particularly dangerous for network infrastructure components that are designed to be accessible from external networks. This characteristic places the vulnerability squarely within ATT&CK framework techniques related to denial of service and network infiltration, where adversaries can leverage weak input validation mechanisms to achieve system disruption. The lack of execution privileges requirement means that even basic network access is sufficient to initiate exploitation attempts against vulnerable modem implementations.
Effective mitigation strategies should focus on implementing comprehensive input validation controls within modem firmware, including strict parameter checking, data type enforcement, and proper error handling mechanisms. Regular firmware updates and security patches should be deployed to address known vulnerabilities, while network segmentation techniques can help limit the potential impact of successful attacks. Additionally, monitoring systems should be implemented to detect anomalous traffic patterns that may indicate exploitation attempts, and access controls should be enforced to restrict unauthorized communication with modem management interfaces.