CVE-2021-25306 in DX600A
Summary
by MITRE • 03/02/2021
A buffer overflow vulnerability in the AT command interface of Gigaset DX600A v41.00-175 devices allows remote attackers to force a device reboot by sending relatively long AT commands.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/14/2021
The buffer overflow vulnerability identified as CVE-2021-25306 affects the Gigaset DX600A device model running firmware version v41.00-175 and represents a critical security flaw within the device's AT command interface. This vulnerability resides in the telecommunications equipment's communication protocol handling mechanism, specifically targeting the command processing subsystem that manages AT commands used for device configuration and control. The AT command interface serves as a fundamental communication channel for administrators to interact with the device, making this flaw particularly concerning as it could be exploited by remote attackers without requiring physical access or authentication credentials. The vulnerability manifests when the device processes AT commands that exceed the allocated buffer size, leading to memory corruption that ultimately results in a device reboot.
The technical implementation of this buffer overflow stems from insufficient input validation and boundary checking within the AT command parsing routine. When an attacker sends an AT command exceeding the predetermined buffer limits, the device fails to properly handle the overflow condition, causing the program stack to become corrupted. This memory corruption directly impacts the device's execution flow, forcing the system to terminate and restart automatically. The vulnerability specifically affects the device's ability to process commands in a safe and predictable manner, creating an opportunity for a denial of service attack that can be executed remotely over the network. This flaw aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation in communication protocols. The attack vector requires only network connectivity to the device's command interface, making it particularly dangerous as it can be exploited from anywhere on the internet.
The operational impact of this vulnerability extends beyond simple device disruption, as it creates potential for more sophisticated attack scenarios that could compromise device integrity and availability. Remote attackers can repeatedly exploit this vulnerability to maintain persistent denial of service conditions, potentially disrupting critical communication services that depend on the device. The automatic reboot functionality provides attackers with a reliable method to keep the device in an unusable state, effectively neutralizing its operational capabilities. From an operational security standpoint, this vulnerability exposes organizations to significant risk as it allows unauthorized parties to compromise the availability of their communication infrastructure without requiring advanced technical skills or physical access. The device's role in telecommunications networks makes this particularly concerning for enterprises and service providers who rely on consistent device availability. This vulnerability maps to ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how seemingly minor protocol implementation flaws can create substantial operational security risks.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from the vendor, which would address the underlying buffer overflow conditions through proper input validation and boundary checking mechanisms. Organizations should implement network segmentation to isolate affected devices from critical network segments and establish monitoring protocols to detect unusual reboot patterns that might indicate exploitation attempts. Network access controls should be configured to restrict access to the AT command interface to authorized administrative networks only, while disabling unnecessary services and protocols. Security teams should also consider implementing intrusion detection systems that can identify patterns of long AT commands being sent to the device, as these would be indicative of exploitation attempts. Additionally, regular vulnerability assessments should be conducted to identify similar flaws in other networked devices and communication equipment within the organization's infrastructure, as this vulnerability demonstrates how legacy communication protocols can contain critical security flaws. The remediation process should include thorough testing of firmware updates in controlled environments before deployment to ensure that the fixes do not introduce compatibility issues with existing network configurations.