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."
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| http://securitytracker.com/id?1030154 | vdb entry third party advisory broken link |
| http://www.osvdb.org/106311 | vdb entry broken link |
| https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-021 | patch vendor advisory |
| http://blogs.technet.com/b/srd/archive/2014/04/30/protection-strategies-for-the-security-advisory-2963983-ie-0day.aspx | broken link mitigation |
| http://secunia.com/advisories/57908 | third party advisory broken link |
| http://www.signalsec.com/cve-2014-1776-ie-0day-analysis/ | third party advisory exploit |
| http://www.fireeye.com/blog/uncategorized/2014/04/new-zero-day-exploit-targeting-internet-explorer-versions-9-through-11-identified-in-targeted-attacks.html | broken link |
| http://www.kb.cert.org/vuls/id/222929 | us government resource third party advisory mitigation |
| https://technet.microsoft.com/library/security/2963983 | patch vendor advisory mitigation |
| http://www.securityfocus.com/bid/67075 | vdb entry third party advisory broken link |