CVE-2017-8077 in TL-SG108E
Summary
by MITRE
On the TP-Link TL-SG108E 1.0, there is a hard-coded ciphering key (a long string beginning with Ei2HNryt). This affects the 1.1.2 Build 20141017 Rel.50749 firmware.
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Analysis
by VulDB Data Team • 09/20/2020
The TP-Link TL-SG108E 1.0 network switch running firmware version 1.1.2 Build 20141017 Rel.50749 contains a critical security flaw involving a hard-coded ciphering key that compromises the device's cryptographic integrity. This vulnerability represents a fundamental design flaw where the manufacturer embedded a static encryption key directly into the firmware code, creating a persistent security weakness that affects all devices running this specific firmware version. The hard-coded key begins with the string Ei2HNryt, which serves as a cryptographic seed for the device's communication protocols and authentication mechanisms.
This flaw fundamentally violates security best practices and aligns with CWE-327, which addresses the use of weak or broken cryptographic algorithms. The presence of a hard-coded key creates a single point of failure where any individual possessing this key can decrypt communications, impersonate legitimate devices, or gain unauthorized access to the network switch's management interfaces. The vulnerability exists at the core of the device's security architecture, making it particularly dangerous as it cannot be easily remediated through standard configuration changes or firmware updates.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables sophisticated attack vectors including man-in-the-middle attacks, session hijacking, and potential network infiltration. Attackers who discover this hard-coded key can exploit it to gain administrative privileges, modify network configurations, or establish persistent backdoors within the network infrastructure. This represents a severe compromise of the device's confidentiality, integrity, and availability properties, as outlined in the CIA triad framework. The vulnerability affects network security posture at the edge of enterprise networks where these switches are commonly deployed, potentially allowing attackers to move laterally through the network once initial access is achieved.
Mitigation strategies for this vulnerability are severely limited due to the embedded nature of the hard-coded key. Organizations should immediately isolate affected devices from critical network segments and implement network segmentation controls to limit potential damage. The most effective remediation involves updating to firmware versions that remove or properly randomize the cryptographic keys, though this may not be possible if the manufacturer has discontinued support for the affected model. Network monitoring solutions should be deployed to detect anomalous communications patterns that might indicate exploitation attempts. This vulnerability demonstrates the critical importance of proper key management practices and adherence to security standards such as those defined in the NIST SP 800-57 guidelines for cryptographic key management, where the use of static keys in production environments constitutes a significant security risk. The incident underscores the need for comprehensive security testing during device development and the implementation of dynamic key generation mechanisms rather than hard-coded solutions.