CVE-2011-4751 in SmarterStats
Summary
by MITRE
SmarterTools SmarterStats 6.2.4100 generates web pages containing external links in response to GET requests with query strings for frmGettingStarted.aspx, which makes it easier for remote attackers to obtain sensitive information by reading (1) web-server access logs or (2) web-server Referer logs, related to a "cross-domain Referer leakage" issue.
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Analysis
by VulDB Data Team • 02/13/2019
The vulnerability identified as CVE-2011-4751 affects SmarterTools SmarterStats version 6.2.4100, presenting a significant information disclosure risk through cross-domain referer leakage. This flaw manifests when the application processes GET requests containing query strings for the frmGettingStarted.aspx page, resulting in the generation of web pages that include external links. The security implications arise from the application's failure to properly sanitize or filter referer information that may contain sensitive data from previous requests. When users navigate to pages containing these external links, the referer header information becomes exposed to external domains, creating an avenue for attackers to harvest sensitive information from server logs.
The technical mechanism behind this vulnerability involves the application's handling of HTTP referer headers during page generation. When frmGettingStarted.aspx processes GET requests with query parameters, it incorporates external links into the generated HTML content without adequate sanitization of referer data. This behavior creates a cross-domain referer leakage scenario where the referer header, which typically contains the URL of the previous page, may include sensitive information such as session tokens, user credentials, or internal resource paths. The vulnerability specifically exploits the fact that web servers log referer information in access logs and referer logs, making sensitive data accessible to remote attackers who can analyze these logs to extract valuable information about user activities and system internals.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to perform reconnaissance activities that could lead to more severe exploits. Attackers can leverage access logs and referer logs to identify user patterns, session information, and potentially sensitive URLs that may contain authentication tokens or other critical data. This information leakage can facilitate targeted attacks such as session hijacking, credential harvesting, or further exploitation of other vulnerabilities within the application or network infrastructure. The vulnerability also violates fundamental security principles regarding information flow control and access control, as it allows unauthorized parties to access information that should remain private within the application's security boundaries.
From a cybersecurity perspective, this vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a specific implementation of cross-domain referer leakage that can be categorized under ATT&CK technique T1071.004 for application layer protocol. The attack vector leverages the trust relationship between web servers and applications, where the server's logging behavior inadvertently exposes sensitive data to unauthorized parties. The remediation approach should focus on implementing proper input validation and output sanitization of referer information, ensuring that external links generated by the application do not propagate sensitive referer data. Organizations should also implement referer header policies that limit the amount of information sent to external domains, and consider implementing proper access controls to restrict log file access to authorized personnel only.
The broader implications of this vulnerability highlight the importance of proper security design in web applications, particularly regarding the handling of sensitive information in HTTP headers and logging mechanisms. Security practitioners should ensure that applications implement comprehensive input validation and output encoding to prevent information leakage through various channels, including referer headers, cookies, and other HTTP metadata. Regular security assessments and code reviews should specifically examine how applications handle external links and referer information to prevent similar vulnerabilities from being introduced during development cycles. Additionally, server-side configurations should be reviewed to ensure that logging practices do not inadvertently expose sensitive information to unauthorized parties, emphasizing the need for proper log access controls and information classification policies across all system components.