CVE-2006-6988 in Slim Browser
Summary
by MITRE
Cross-domain vulnerability in Slim Browser 4.07 build 100 allows remote attackers to access restricted information from other domains via an object tag with a data parameter that references a link on the attacker s originating site that specifies a Location HTTP header that references the target site, which then makes that content available through the outerHTML attribute of the object, a similar vulnerability to CVE-2006-3280.
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Analysis
by VulDB Data Team • 10/10/2017
This vulnerability exists within Slim Browser version 4.07 build 100 and represents a cross-domain information disclosure flaw that exploits the browser's handling of object tags and HTTP headers. The vulnerability specifically leverages the data parameter within an object tag to reference content from an attacker-controlled domain, creating a pathway for unauthorized data access across domain boundaries. The attack mechanism involves the attacker's originating site sending a Location HTTP header that points to the target site, enabling the browser to retrieve content from the target domain and expose it through the outerHTML attribute of the object element. This represents a classic cross-site scripting or cross-domain data leakage vulnerability where the browser's security model is bypassed through improper handling of cross-domain resource references. The vulnerability is particularly concerning because it allows remote attackers to access restricted information that should normally be protected by cross-domain security policies, effectively breaking down the isolation mechanisms that prevent unauthorized access between different domains.
The technical flaw stems from the browser's insufficient validation of cross-domain references when processing object tags with data parameters. When a browser encounters an object tag with a data attribute pointing to a remote resource, it should enforce strict cross-domain security policies to prevent unauthorized access to resources from different origins. However, in this case, the browser fails to properly validate the Location HTTP header response and the subsequent content exposure through outerHTML, creating a pathway for attackers to retrieve content from protected domains. This vulnerability operates on the principle that browsers should not allow one domain to access content from another domain unless explicit permission is granted through mechanisms like CORS headers or similar cross-domain access controls. The flaw essentially allows attackers to create a proxy-like mechanism where content from a target domain is retrieved and exposed through the object tag's outerHTML attribute, bypassing normal security boundaries that should prevent such access.
The operational impact of this vulnerability is significant as it enables remote attackers to access restricted information from other domains without proper authentication or authorization. This could potentially allow attackers to extract sensitive data, credentials, or other confidential information that should be protected by cross-domain security policies. The vulnerability affects web applications and services that rely on browser-based security mechanisms to protect against cross-domain access attempts, creating a potential attack surface that could be exploited to compromise the confidentiality of information stored on target domains. The similarity to CVE-2006-3280 indicates this is part of a broader class of vulnerabilities affecting web browsers' handling of cross-domain references, where object tags and HTTP headers are manipulated to bypass security restrictions. This type of vulnerability can be particularly dangerous in environments where users access multiple domains or applications that share common security contexts.
Mitigation strategies for this vulnerability should focus on implementing proper cross-domain security controls within the browser's object tag processing logic. Browser vendors should ensure that HTTP headers, particularly Location headers, are properly validated before content is exposed through DOM attributes like outerHTML. The implementation should enforce strict origin-based access controls and prevent unauthorized cross-domain content exposure through object elements. This vulnerability aligns with CWE-94, which covers "Improper Control of Generation of Code," and relates to ATT&CK technique T1190, "Exploit Public-Facing Application," as it represents an attack vector through web browser components. Users should update to patched versions of Slim Browser that properly handle cross-domain references and HTTP headers to prevent exploitation of this vulnerability. Additionally, administrators should consider implementing network-level controls and monitoring to detect suspicious cross-domain access patterns that might indicate exploitation attempts of this type of vulnerability.