CVE-2026-21555 in UDX710
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 input validation flaw that exists within modem firmware or software components, potentially allowing attackers to execute remote denial of service attacks without requiring any elevated privileges or execution rights. The weakness stems from inadequate sanitization and validation of input data received by the modem's processing units, creating opportunities for malicious actors to craft specially designed inputs that can cause the modem to crash or become unresponsive. Such vulnerabilities typically manifest when the modem fails to properly validate the length, format, or content of incoming data streams, protocol messages, or configuration parameters. The impact extends beyond simple service disruption as this weakness can affect network connectivity for devices relying on the compromised modem, potentially leading to widespread communication outages in affected networks.
The technical implementation of this vulnerability involves the modem's failure to enforce proper input boundaries and validation checks during data processing operations. When legitimate input validation mechanisms are bypassed or inadequately implemented, attackers can exploit this gap by sending malformed packets, oversized data structures, or crafted protocol messages that cause buffer overflows, memory corruption, or resource exhaustion within the modem's operational environment. This type of vulnerability aligns with common weakness enumerations such as CWE-20, which describes improper input validation, and may also relate to CWE-129, concerning insufficient input validation. The attack surface becomes particularly dangerous when considering that modems often serve as critical network infrastructure components in various environments including enterprise networks, home gateways, and mobile communication systems where reliability is paramount.
From an operational perspective, this vulnerability presents significant risk to network availability and service continuity, particularly in scenarios where modems function as primary communication pathways for critical infrastructure or business operations. Attackers can leverage this weakness to perform remote denial of service attacks that may persist until manual intervention or system reboot occurs, potentially causing extended service interruptions that affect multiple users or devices simultaneously. The lack of requirement for additional execution privileges makes this attack vector particularly concerning as it reduces the barrier to successful exploitation and increases the potential impact across diverse network environments. Network administrators must consider that such vulnerabilities can be exploited by adversaries with minimal technical expertise, making them attractive targets for both opportunistic attacks and more organized threat campaigns targeting specific infrastructure components.
Mitigation strategies should focus on implementing robust input validation mechanisms within modem firmware and software components, including comprehensive data sanitization routines, proper buffer management protocols, and regular security updates to address known vulnerabilities. Organizations should deploy network monitoring solutions capable of detecting anomalous traffic patterns that may indicate exploitation attempts, while also ensuring that modem configurations follow security best practices such as disabling unnecessary services and implementing access controls. The remediation process requires firmware vendors to conduct thorough code reviews and vulnerability assessments, particularly focusing on input handling routines and memory management functions, with regular patch deployment schedules to address identified weaknesses. Additionally, network segmentation strategies can help limit the potential impact of exploitation by isolating vulnerable modem components from critical network segments and implementing proper firewall rules to restrict potentially malicious traffic patterns that could exploit this input validation deficiency.