CVE-2014-1776
Published: 27 April 2014
Summary
CVE-2014-1776 is a critical-severity Use After Free (CWE-416) vulnerability in Microsoft Windows Server 2008. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 0.7% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 CM-7 (Least Functionality) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2014-1776 is a use-after-free vulnerability, tracked under CWE-416, that affects Microsoft Internet Explorer versions 6 through 11. It resides in the handling of markup connections via the CMarkup::IsConnectedToPrimaryMarkup function and can result in memory corruption. The issue was originally associated with VGX.DLL in early reporting, though Microsoft later clarified that the DLL itself does not contain the vulnerable code.
Remote attackers can exploit the flaw by serving specially crafted web content that triggers the use-after-free condition. Successful exploitation grants arbitrary code execution or a denial-of-service condition on the target system, and the vulnerability was observed being leveraged in the wild during April 2014.
Microsoft and other vendors published guidance emphasizing immediate workarounds such as disabling VGX.DLL to block known attack variants, along with the availability of security updates that address the underlying flaw. FireEye and CERT coordination reports further detail targeted attack campaigns and recommend applying patches or implementing network-level protections outlined in the associated security advisories.
The vulnerability was actively exploited in targeted attacks before a patch was released, confirming its status as a zero-day used against Internet Explorer 9 through 11 in real-world campaigns.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2014-1850
Vulnerability details
Use-after-free vulnerability in Microsoft Internet Explorer 6 through 11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via vectors related to the CMarkup::IsConnectedToPrimaryMarkup function, as exploited in the wild in April 2014. NOTE:…
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this issue originally emphasized VGX.DLL, but Microsoft clarified that "VGX.DLL does not contain the vulnerable code leveraged in this exploit. Disabling VGX.DLL is an exploit-specific workaround that provides an immediate, effective workaround to help block known attacks."
- CWE(s)
- KEV Date Added
- 28 January 2022
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires applying vendor security updates that remediate the use-after-free flaw in IE before exploitation succeeds.
Enforces disabling unnecessary components such as VGX.DLL and restricting browser features to block the specific attack vector described.
Controls execution of mobile code delivered via web content, limiting the attack surface that triggers the CMarkup use-after-free condition.