CVE-2019-15654 in AP2600-I
Summary
by MITRE
Comba AC2400 devices are prone to password disclosure via a simple crafted /09/business/upgrade/upcfgAction.php?download=true request to the web management server. The request doesn't require any authentication and will lead to saving the DBconfig.cfg file. At the end of the file, the login information is stored in cleartext.
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Analysis
by VulDB Data Team • 04/18/2024
The CVE-2019-15654 vulnerability affects Comba AC2400 wireless routers and represents a critical security flaw in the device's web management interface. This vulnerability stems from improper access controls and insecure configuration file handling within the router's firmware. The flaw exists in the upcfgAction.php script located at /09/business/upgrade/ path, which serves as an endpoint for firmware upgrade operations. Security researchers discovered that this endpoint lacks proper authentication mechanisms, allowing any remote attacker to exploit the vulnerability without requiring valid credentials or administrative privileges.
The technical implementation of this vulnerability involves a simple HTTP GET request with the parameter download=true that triggers the router's configuration file download functionality. When this request is processed, the system automatically saves the DBconfig.cfg file to the device's storage without requiring any form of authentication or authorization. This configuration file contains critical system information including network settings, service configurations, and most importantly, administrative login credentials stored in plain text format. The cleartext storage of passwords violates fundamental security principles and creates an immediate risk for unauthorized access to the device's management interface.
The operational impact of this vulnerability extends beyond simple credential theft, as it provides attackers with complete administrative control over the affected router. Once the DBconfig.cfg file is downloaded, attackers can extract the administrative username and password combination, allowing them to log into the router's web management interface and modify network settings, configure firewall rules, change DNS configurations, or even install malicious firmware. This type of vulnerability directly aligns with CWE-312 (Cleartext Storage of Sensitive Information) and represents a classic example of insecure credential storage practices. The attack vector is particularly concerning because it requires no prior authentication, making it accessible to any network user who can reach the device's management interface.
From an adversarial perspective, this vulnerability maps directly to several ATT&CK techniques including T1078 (Valid Accounts) for credential access and T1046 (Network Service Scanning) for identifying vulnerable devices on the network. The low complexity and high impact nature of this flaw makes it attractive to automated exploitation tools and opportunistic attackers. Organizations with Comba AC2400 devices in their network infrastructure face significant risk of unauthorized access, potential man-in-the-middle attacks, and compromised network security. The vulnerability affects not only individual devices but also creates potential lateral movement opportunities for attackers who may use stolen credentials to access other network resources.
The recommended mitigations for CVE-2019-15654 include immediate firmware updates from Comba or the device manufacturer, which should address the authentication bypass and properly secure the configuration file download endpoint. Network administrators should also implement network segmentation to isolate IoT devices from critical network segments, disable unnecessary services, and regularly audit device configurations. Additionally, the use of network monitoring tools can help detect unauthorized access attempts to management interfaces. Organizations should also consider implementing strong password policies, enabling multi-factor authentication where possible, and conducting regular security assessments to identify similar vulnerabilities in other network devices. The vulnerability highlights the importance of secure coding practices and proper access control implementation in embedded systems and network appliances.