CVE-2017-0210
Microsoft Internet Explorer Privilege Escalation Vulnerability
Description
CVE-2017-0210 is a privilege escalation vulnerability in Microsoft Internet Explorer caused by improper enforcement of cross-domain policies. The vulnerability allows an attacker to access information from one domain while browsing a page in another domain, effectively bypassing the same-origin policy that is a fundamental browser security mechanism. By luring a user to a crafted website or embedding malicious content, an attacker could steal sensitive data or execute actions in the context of the victim's authenticated sessions. CVE-2017-0210 has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog, and its EPSS percentile of 97.1% indicates a very high likelihood of exploitation.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | internet explorer | 10; 11 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- http://www.securityfocus.com/bid/97512(Broken Link, Third Party Advisory, VDB Entry)
- http://www.securitytracker.com/id/1038238(Broken Link, Third Party Advisory, VDB Entry)
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0210(Patch, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-0210(US Government Resource)
Weakness Type
CWE-284: Improper Access Control
CWE-284 describes a weakness where a product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. In CVE-2017-0210, Internet Explorer fails to properly enforce cross-domain policies, allowing scripts from one web domain to access content and data belonging to another domain. This violates the same-origin policy and enables unauthorized cross-domain information access.
Learn more: CWE-284 — Improper Access Control
Impact Analysis
CVE-2017-0210 enables cross-domain information theft through Internet Explorer by exploiting a failure in same-origin policy enforcement. The vulnerability is remotely exploitable when a user visits a crafted web page, requiring user interaction but no authentication from the attacker's perspective. The primary impact is on confidentiality, as an attacker can read data from other domains the user is currently authenticated to, including session tokens, personal information, and form data. This can be escalated to an integrity impact when the attacker uses the stolen session information to perform actions on behalf of the victim. The EPSS percentile of 97.1% reflects very high exploitation activity. CISA has confirmed active exploitation in the wild and added CVE-2017-0210 to the KEV catalog, underscoring the urgency of remediation for organizations still running Internet Explorer.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2017-0210 and added it to the Known Exploited Vulnerabilities catalog with a remediation deadline of June 14, 2022. The EPSS percentile of 97.1% indicates very high real-world exploitation probability. Cross-domain policy bypass vulnerabilities in Internet Explorer are highly valued by attackers because they enable silent theft of credentials and session tokens from authenticated web applications. Such vulnerabilities have historically been used in both targeted attacks and broader exploit kit campaigns to harvest authentication data from victims visiting malicious or compromised web pages.
Remediation
- Apply Microsoft security updates as directed by the vendor. This is the required remediation action per CISA's KEV catalog entry for CVE-2017-0210.
- Migrate away from Internet Explorer to a modern browser such as Microsoft Edge, Google Chrome, or Mozilla Firefox, as Internet Explorer has reached end of life and no longer receives security updates.
- If Internet Explorer must remain temporarily in use, restrict it to trusted internal sites only through Group Policy settings and Internet Explorer Security Zones.
- Implement Content Security Policy (CSP) headers on web applications to provide additional defense-in-depth against cross-domain data theft.
- Monitor authentication logs for suspicious activity that could indicate session hijacking, particularly from users known to still use Internet Explorer.
Technical Details
CVE-2017-0210 exploits a flaw in Internet Explorer's enforcement of the same-origin policy, the browser security mechanism that prevents scripts from one origin from accessing data belonging to another origin. The vulnerability falls under CWE-284 (Improper Access Control), where the browser fails to properly validate the domain context during certain cross-domain operations. When a victim navigates to a crafted page, attacker-controlled scripts can bypass the cross-domain boundary and access content from other domains that the user has active sessions with. The attack vector is network-based, requiring the victim to visit a malicious page, but the exploitation complexity is low once the user navigates to the attacker's content. This privilege escalation occurs within the browser context rather than at the operating system level, but the impact is severe as it enables theft of authenticated session data across all domains the victim is logged into.
Frequently Asked Questions
Is CVE-2017-0210 being actively exploited?
Yes, CVE-2017-0210 has been actively exploited in the wild. CISA has confirmed active exploitation and added it to the KEV catalog. The EPSS percentile of 97.1% reflects very high exploitation probability, driven by the value of cross-domain policy bypass vulnerabilities for session theft and credential harvesting.
What products are affected by CVE-2017-0210?
CVE-2017-0210 affects Microsoft Internet Explorer. Multiple versions of Internet Explorer across Windows platforms are affected. Internet Explorer has reached end of life and should be replaced with a modern browser.
How do I fix CVE-2017-0210?
Apply the Microsoft security update for CVE-2017-0210 and migrate away from Internet Explorer to a modern browser. If temporary use is required, restrict Internet Explorer to trusted sites through Group Policy. See the Remediation section for detailed steps.
How severe is CVE-2017-0210?
CVE-2017-0210 is a privilege escalation vulnerability that bypasses browser same-origin policy protections, enabling cross-domain data theft. Its EPSS percentile of 97.1% indicates very high exploitation probability. While it requires user interaction, the ability to steal authenticated session data from other domains makes it a significant threat to user privacy and account security.
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