CVE-2016-1135 in BHR-4GRV2
Summary
by MITRE
Cross-site scripting (XSS) vulnerability on BUFFALO BHR-4GRV2 devices with firmware 1.04 and earlier, WEX-300 devices with firmware 1.90 and earlier, WHR-1166DHP devices with firmware 1.90 and earlier, WHR-300HP2 devices with firmware 1.90 and earlier, WHR-600D devices with firmware 1.90 and earlier, WMR-300 devices with firmware 1.90 and earlier, WMR-433 devices with firmware 1.01 and earlier, and WSR-1166DHP devices with firmware 1.01 and earlier allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 06/28/2018
The CVE-2016-1135 vulnerability represents a critical cross-site scripting flaw affecting multiple Buffalo network devices including BHR-4GRV2, WEX-300, WHR-1166DHP, WHR-300HP2, WHR-600D, WMR-300, WMR-433, and WSR-1166DHP models. This vulnerability resides within the web-based management interfaces of these wireless routers and access points, making it particularly dangerous as it can be exploited by remote attackers without requiring physical access or authentication. The affected firmware versions span several major releases, indicating this was a widespread issue across Buffalo's product line that persisted for an extended period. The vulnerability's classification as a CWE-79 - Improper Neutralization of Input During Web Page Generation indicates that the devices fail to properly sanitize user-supplied input before incorporating it into dynamically generated web content, creating an environment where malicious scripts can be executed in the context of authenticated users.
The technical exploitation of this vulnerability occurs through unspecified vectors within the web interface, suggesting that multiple input points across the device management portals could be compromised. Attackers can inject arbitrary web script or HTML code that gets executed when legitimate users access the affected web interfaces. This typically involves manipulating form fields, URL parameters, or other user-controllable inputs that are not properly validated or escaped before being rendered in web pages. The impact extends beyond simple script execution as it can enable attackers to steal session cookies, perform actions on behalf of authenticated users, redirect victims to malicious sites, or even install persistent backdoors on the affected devices. The vulnerability's presence in firmware versions up to 1.01 and 1.90 indicates that manufacturers failed to adequately address this issue in their security updates, leaving millions of devices exposed to potential exploitation.
The operational impact of CVE-2016-1135 is severe and multifaceted for both individual users and enterprise networks. Once exploited, attackers can gain unauthorized access to device configurations, potentially compromising entire network infrastructures by modifying router settings, creating backdoor access points, or redirecting traffic through malicious servers. The vulnerability particularly threatens home users who may not be aware of the security risks associated with their network devices, while enterprise environments face additional risks as compromised routers can serve as entry points for broader network infiltration. The attack surface is significantly expanded due to the web-based nature of the vulnerability, meaning that attackers can target these devices from anywhere on the internet, making them attractive targets for automated scanning and exploitation campaigns. This vulnerability directly maps to ATT&CK technique T1071.004 - Application Layer Protocol: DNS, where compromised devices could be used to establish command and control channels or relay malicious traffic, and T1566 - Phishing, as attackers could use the compromised devices to redirect users to malicious sites or inject phishing content into legitimate web sessions.
Organizations and users affected by this vulnerability should prioritize immediate firmware updates from Buffalo's official support channels, as these releases typically contain patches addressing the XSS flaws in the web interfaces. Network administrators should implement additional monitoring measures to detect unusual traffic patterns that might indicate exploitation attempts, while also considering network segmentation to limit the potential impact should devices become compromised. Security teams should conduct comprehensive vulnerability assessments across all networked devices to identify similar unpatched systems that may be vulnerable to similar attacks, as this represents a common class of vulnerability in embedded network devices. The vulnerability also highlights the importance of implementing proper input validation and output encoding practices in web applications, particularly those running on embedded systems where resource constraints may lead to security shortcuts. Organizations should consider deploying web application firewalls or network-based intrusion detection systems to monitor for exploitation attempts targeting these specific device types, as the attack patterns associated with XSS vulnerabilities typically follow predictable signatures that can be detected through proper monitoring.