CVE-2022-36615 in A3000RU
Summary
by MITRE • 08/29/2022
TOTOLINK A3000RU V4.1.2cu.5185_B20201128 was discovered to contain a hardcoded password for root at /etc/shadow.sample.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/09/2022
The vulnerability identified as CVE-2022-36615 represents a critical security flaw in the TOTOLINK A3000RU router firmware version V4.1.2cu.5185_B20201128. This issue stems from the improper configuration of system authentication credentials within the device's firmware, specifically exposing a hardcoded root password that persists in the system's shadow file. The presence of such credentials in a publicly accessible configuration file creates an immediate and severe security risk for all devices running this firmware version. The vulnerability directly violates fundamental security principles by embedding administrative credentials within the software itself rather than implementing proper dynamic authentication mechanisms. This flaw falls under the category of hardcoded credentials, which is classified as CWE-798 in the Common Weakness Enumeration framework, representing one of the most dangerous types of vulnerabilities in embedded systems and network devices. The discovery of these credentials in the /etc/shadow.sample file indicates that the manufacturer failed to properly sanitize or remove development artifacts before releasing the firmware to production environments.
The technical exploitation of this vulnerability allows unauthorized attackers to gain immediate root access to the affected router through a simple authentication process. Since the password is hardcoded and stored in a configuration file that remains accessible to all users of the device, any individual with network access can easily retrieve the credentials and establish administrative control over the router. This provides attackers with complete control over the device's network configuration, firewall settings, DNS resolution, and all other router functions. The attack vector is particularly concerning as it requires no complex exploitation techniques or privilege escalation methods, making it extremely accessible to attackers with minimal technical expertise. The vulnerability enables potential attackers to modify network settings, redirect traffic, install malicious firmware, or use the device as a pivot point for further attacks within the local network. This type of access can facilitate advanced persistent threats and allows attackers to establish long-term control over the network infrastructure without detection.
The operational impact of CVE-2022-36615 extends beyond simple unauthorized access to encompass significant risks for network security and privacy. Once an attacker gains root access through this hardcoded credential, they can manipulate the router's core networking functions, potentially disrupting legitimate network traffic or creating backdoors for continued access. The vulnerability affects all devices running the specific firmware version, creating a widespread security concern across networks that may not be immediately aware of their exposure. Organizations and individuals using these devices face potential data breaches, network infiltration, and loss of network control, as the attacker can modify routing tables, disable security features, or redirect network traffic to malicious destinations. The attack surface expands significantly as compromised routers can serve as launching points for attacks against other networked devices, potentially enabling lateral movement throughout the network infrastructure. This vulnerability directly aligns with tactics described in the MITRE ATT&CK framework under the initial access and privilege escalation domains, specifically targeting the use of default credentials and credential access techniques.
Mitigation strategies for CVE-2022-36615 must prioritize immediate firmware updates from the manufacturer, as this represents the most effective solution to address the hardcoded credential issue. Network administrators should implement network segmentation and monitoring to detect unauthorized access attempts or unusual network behavior that might indicate exploitation of this vulnerability. The implementation of network access control lists and firewall rules can help limit the impact of a compromised device by restricting communication between the affected router and other network segments. Regular vulnerability assessments and penetration testing should be conducted to identify similar hardcoded credentials in other network devices and firmware components. Organizations should establish robust patch management processes that include immediate deployment of security updates for all network infrastructure devices. The vulnerability also underscores the importance of secure development practices and proper configuration management, requiring manufacturers to implement proper credential handling procedures and eliminate hardcoded authentication values in production firmware releases. Network monitoring solutions should be configured to detect and alert on unusual authentication patterns or attempts to access system configuration files that may indicate exploitation attempts.