CVE-2018-6529 in DIR-860L
Summary
by MITRE
XSS vulnerability in htdocs/webinc/js/bsc_sms_inbox.php in D-Link DIR-868L DIR868LA1_FW112b04 and previous versions, DIR-865L DIR-865L_REVA_FIRMWARE_PATCH_1.08.B01 and previous versions, and DIR-860L DIR860LA1_FW110b04 and previous versions allows remote attackers to read a cookie via a crafted Treturn parameter to soap.cgi.
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Analysis
by VulDB Data Team • 01/10/2020
This cross-site scripting vulnerability exists in D-Link router firmware versions affecting multiple models including DIR-868L, DIR-865L, and DIR-860L. The flaw is located in the web interface component at htdocs/webinc/js/bsc_sms_inbox.php and specifically manifests when processing the Treturn parameter through the soap.cgi endpoint. The vulnerability stems from inadequate input validation and output sanitization of user-supplied data, allowing malicious actors to inject arbitrary script code into the web application's response. This particular implementation allows attackers to manipulate the Treturn parameter which is then processed without proper encoding or validation, creating a direct path for script injection attacks.
The technical exploitation of this vulnerability follows a standard XSS attack pattern where an attacker crafts a malicious payload containing script code and injects it through the vulnerable Treturn parameter. When the affected router processes this parameter in soap.cgi, the unvalidated input gets reflected back to the user's browser, executing the malicious script within the context of the router's web interface. The impact is significant as cookies containing session information or authentication tokens can be read by the attacker, potentially enabling session hijacking or privilege escalation attacks. This vulnerability falls under CWE-79 - Improper Neutralization of Input During Web Page Generation, which is a core weakness in web application security.
The operational impact extends beyond simple cookie theft as this vulnerability could enable attackers to perform actions within the router's administrative interface that they should not be authorized to perform. Given that these routers are typically deployed in home and small office environments, the attack surface is considerable with potential for network compromise. The vulnerability affects multiple firmware versions, indicating it was likely a persistent flaw in the web application codebase that was not properly addressed in the affected releases. This represents a critical security gap in the router's web interface, as the attack vector is accessible over the network without requiring authentication.
Mitigation strategies should include immediate firmware updates from D-Link to address the identified vulnerability, as well as network segmentation to limit access to the router's web interface. Organizations should implement proper input validation and output encoding mechanisms, following OWASP secure coding practices. The vulnerability demonstrates the importance of securing web applications within embedded devices and aligns with ATT&CK technique T1212 - Exploitation for Credential Access, as it provides a pathway for attackers to obtain session tokens and credentials. Network administrators should also consider disabling unnecessary web interfaces and implementing web application firewalls to detect and prevent such attacks. The vulnerability highlights the critical need for proper security testing of embedded web applications and demonstrates how seemingly minor input validation flaws can lead to significant security implications in network infrastructure devices.