CVE-2011-4836 in HomeSeer HS2
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the web interface in HomeSeer HS2 2.5.0.20 allows remote attackers to inject arbitrary web script or HTML via a request for a crafted URI.
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Analysis
by VulDB Data Team • 08/08/2024
The vulnerability identified as CVE-2011-4836 represents a critical cross-site scripting flaw within the web interface of HomeSeer HS2 version 2.5.0.20. This issue stems from inadequate input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before rendering it within the web application's response. The vulnerability specifically manifests when the application processes requests containing crafted URIs that contain malicious script code, allowing attackers to execute arbitrary web scripts or HTML content within the context of other users' browsers. The flaw exists at the application layer where user input is directly incorporated into dynamic web pages without proper sanitization or context-appropriate encoding, creating an environment where malicious payloads can be injected and subsequently executed by unsuspecting victims who visit the compromised pages.
The technical exploitation of this vulnerability follows a standard XSS attack pattern where remote attackers craft malicious URIs containing script payloads that are then processed by the vulnerable HomeSeer web interface. When legitimate users access these crafted URLs, the malicious code executes within their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability is classified as a classic stored or reflected XSS issue depending on how the input is handled within the application, but regardless of the variant, the fundamental flaw lies in the application's failure to properly validate and encode user input before incorporating it into web responses. This weakness directly violates security principles outlined in the OWASP Top Ten, specifically addressing the category of injection vulnerabilities that can lead to unauthorized access and data compromise.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to manipulate the web interface functionality and potentially escalate privileges within the HomeSeer environment. Attackers could leverage this vulnerability to steal session cookies, modify user permissions, or gain unauthorized access to home automation controls that are managed through the vulnerable web interface. The attack surface is particularly concerning given that HomeSeer systems are often deployed in residential and commercial environments where they control critical home automation functions, making this vulnerability not just a technical concern but a potential physical security risk. The vulnerability also aligns with ATT&CK technique T1566 which covers social engineering through malicious web content, and may contribute to broader attack chains that could lead to persistent access or lateral movement within networked environments.
Organizations utilizing HomeSeer HS2 2.5.0.20 should implement immediate mitigations including input validation and output encoding measures to prevent unauthorized script injection. The most effective approach involves implementing proper context-appropriate encoding for all user-supplied data before rendering it within web pages, which directly addresses the underlying CWE-79 weakness related to cross-site scripting. Additional protective measures include implementing content security policies, using secure session management practices, and regularly updating the application to versions that have addressed this vulnerability. Network-level protections such as web application firewalls and intrusion detection systems can provide additional layers of defense, though these should not be relied upon as the sole mitigation strategy. The vulnerability also underscores the importance of regular security assessments and vulnerability scanning to identify similar weaknesses in other web applications within the organization's infrastructure, particularly those handling user input through web interfaces.