CVE-2017-8498 in Edge
Summary
by MITRE
Microsoft Edge in Windows 10 1607 and 1703, and Windows Server 2016 allows an attacker to read data not intended to be disclosed when Edge allows JavaScript XML DOM objects to detect installed browser extensions, aka "Microsoft Edge Information Disclosure Vulnerability". This CVE ID is unique from CVE-2017-8504.
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Analysis
by VulDB Data Team • 10/18/2019
The vulnerability identified as CVE-2017-8498 represents a critical information disclosure flaw within Microsoft Edge browser that affected Windows 10 versions 1607 and 1703, as well as Windows Server 2016. This security weakness stems from the browser's handling of JavaScript XML Document Object Model (DOM) objects, creating an unintended pathway for attackers to access sensitive data that should remain protected from unauthorized disclosure. The flaw specifically manifests when Edge permits JavaScript code to detect and enumerate installed browser extensions, which inadvertently exposes information about the browser's extension ecosystem and potentially sensitive user data. This vulnerability operates under the broader category of information disclosure weaknesses that fall under CWE-200, which encompasses the exposure of sensitive information to an unauthorized actor.
The technical execution of this vulnerability relies on the manipulation of JavaScript XML DOM objects within the Edge browser environment. When JavaScript code attempts to interact with XML DOM structures, it can exploit a flaw in how Edge processes these interactions, allowing for the detection of installed browser extensions through indirect means. This occurs because the browser's implementation does not properly restrict access to extension-related information when JavaScript XML DOM objects are manipulated, creating a data leakage channel. The flaw essentially allows attackers to gather metadata about installed extensions, potentially including extension names, versions, and other identifying characteristics that could be leveraged for further exploitation or reconnaissance activities. This behavior violates fundamental security principles of information hiding and access control that should prevent unauthorized data access.
The operational impact of CVE-2017-8498 extends beyond simple information disclosure, as it creates potential attack vectors for more sophisticated threats. An attacker who successfully exploits this vulnerability could gather detailed information about a user's browsing environment, including installed extensions that might have known security vulnerabilities or could be targeted for exploitation. This information could be used to craft targeted attacks against specific browser extensions, potentially leading to privilege escalation or further system compromise. The vulnerability also poses risks to user privacy and confidentiality, as it could expose browsing habits and preferences through extension detection. From an attacker's perspective, this information could be combined with other reconnaissance data to build comprehensive profiles of target users, making it particularly dangerous in targeted attack scenarios. The vulnerability's classification under the ATT&CK framework would likely fall under T1082 (System Information Discovery) and potentially T1566 (Phishing) as part of broader reconnaissance activities.
Mitigation strategies for CVE-2017-8498 should prioritize immediate patching of affected systems, as Microsoft released security updates to address this specific vulnerability. Organizations should ensure all Windows 10 systems running versions 1607 and 1703, as well as Windows Server 2016 installations, receive the applicable security updates. Network administrators should implement monitoring for suspicious JavaScript activity that might indicate attempts to exploit this vulnerability, particularly around XML DOM manipulation patterns. Additionally, browser security policies should be reviewed and enhanced to restrict access to extension-related APIs when not explicitly required for legitimate functionality. The vulnerability highlights the importance of proper input validation and access control mechanisms in web browser implementations, particularly when handling cross-origin resource requests and extension information access. Organizations should also consider implementing additional security measures such as browser sandboxing, content security policies, and regular security assessments to prevent similar vulnerabilities from being exploited in their environments.