CVE-2018-15748 in 2335dn
Summary
by MITRE
On Dell 2335dn printers with Printer Firmware Version 2.70.05.02, Engine Firmware Version 1.10.65, and Network Firmware Version V4.02.15(2335dn MFP) 11-22-2010, the admin interface allows an authenticated attacker to retrieve the configured SMTP or LDAP password by viewing the HTML source code of the Email Settings webpage. In some cases, authentication can be achieved with the blank default password for the admin account. NOTE: the vendor indicates that this is an "End Of Support Life" product.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 03/17/2020
This vulnerability exists in Dell 2335dn multifunction printers running specific firmware versions where sensitive authentication credentials are improperly exposed through the web-based administration interface. The flaw occurs when an authenticated attacker accesses the Email Settings webpage and examines the HTML source code, revealing plaintext SMTP and LDAP passwords that are stored in the configuration. This represents a critical misconfiguration in how the device handles credential storage and presentation, allowing for unauthorized access to email and directory services that the printer uses for communication and user authentication. The vulnerability is particularly concerning because it directly exposes network credentials that could enable lateral movement within an organization's infrastructure.
The technical implementation of this flaw stems from improper handling of sensitive data within the printer's web interface. When the administrator configures email settings or LDAP integration, the system stores these credentials in the device's memory and subsequently displays them in the HTML source code of the configuration pages. This violates fundamental security principles of credential management and demonstrates poor separation between configuration data and presentation layer elements. The vulnerability is classified under CWE-200 as exposure of sensitive information and aligns with CWE-312 for exposure of sensitive data in the clear. The attacker does not require advanced exploitation techniques since the credentials are readily available in the source code, making this a straightforward privilege escalation vector.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables potential attackers to compromise the entire email communication infrastructure that the printer relies upon. An attacker who gains access to these credentials could intercept email communications, relay messages through the printer's email server, or use the credentials to authenticate to LDAP directories for further reconnaissance. This vulnerability also represents a significant risk for organizations using these printers in enterprise environments where the printer might be configured with elevated privileges or access to sensitive internal systems. The printer's role as a networked device makes it a potential entry point for attackers seeking to establish persistence or move laterally within the network. According to ATT&CK framework, this vulnerability maps to T1078 for valid accounts and T1566 for credential access, demonstrating how misconfigured network devices can serve as attack vectors for broader compromise.
Mitigation strategies for this vulnerability should focus on immediate remediation through firmware updates, though the vendor has marked this product as end-of-life, limiting available patches. Organizations should consider network segmentation to isolate these devices from critical systems, implement strict access controls for the printer administration interface, and regularly audit printer configurations to identify exposed credentials. The printer should be configured to use more secure authentication methods and access controls, with regular credential rotation policies. Network monitoring should be implemented to detect unusual email traffic patterns that might indicate credential misuse. Additionally, administrators should disable unnecessary services and features on these devices, as the presence of multiple network services increases attack surface. The vulnerability highlights the importance of proper credential management in embedded systems and the need for regular security assessments of legacy networked devices, particularly those that are no longer supported by vendors. Organizations should develop contingency plans for retiring unsupported devices and transitioning to more secure, modern alternatives that receive regular security updates and support.