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CVE-2014-1776: Microsoft Internet Explorer Memory Corruption Vulnerability

CVE-2014-1776 is rated critical with a CVSS v3.1 base score of 9.8 and affects Microsoft Internet Explorer. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-01-28, which means exploitation in the wild has been observed.

Vulnerability description

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: 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."

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-416: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

Affected products

• Microsoft Internet Explorer: 6; 7; 8; 9; 10; 11

References

• https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-021
• https://technet.microsoft.com/library/security/2963983
• http://blogs.technet.com/b/srd/archive/2014/04/30/protection-strategies-for-the-security-advisory-2963983-ie-0day.aspx
• http://www.kb.cert.org/vuls/id/222929
• http://securitytracker.com/id?1030154
• http://www.securityfocus.com/bid/67075
• http://www.signalsec.com/cve-2014-1776-ie-0day-analysis/
• https://www.vicarius.io/vsociety/posts/cve-2014-1776-use-after-free-vulnerability-in-microsoft-internet-explorer-detection-script
• https://www.vicarius.io/vsociety/posts/cve-2014-1776-use-after-free-vulnerability-in-microsoft-internet-explorer-mitigation-scripts
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2014-1776
• http://secunia.com/advisories/57908
• http://www.fireeye.com/blog/uncategorized/2014/04/new-zero-day-exploit-targeting-internet-explorer-versions-9-through-11-identified-in-targeted-attacks.html
• http://www.osvdb.org/106311