CVE-2013-3893 — Internet Explorer
HIGHCVE-2013-3893 is a high-severity (CVSS 8.8) Use After Free vulnerability in microsoft internet explorer. It is in CISA's Known Exploited Vulnerabilities catalog (added 2025-08-12) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
Use-after-free vulnerability in the SetMouseCapture implementation in mshtml.dll in Microsoft Internet Explorer 6 through 11 allows remote attackers to execute arbitrary code via crafted…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2025-08-12. Federal agencies were required to remediate by 2025-09-02.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2013-3893.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2013-3893 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 395,249 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Use-after-free vulnerability in the SetMouseCapture implementation in mshtml.dll in Microsoft Internet Explorer 6 through 11 allows remote attackers to execute arbitrary code via crafted JavaScript strings, as demonstrated by use of an ms-help: URL that triggers loading of hxds.dll.
Affected Products
internet explorermicrosoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Micorosft Internet Explorer - SetMouseCapture Use-After-Free (Metasploit)
by Metasploit · Oct 2, 2013
Microsoft Internet Explorer 8 - 'SetMouseCapture ' Use After Free
by SlidingWindow · May 17, 2021
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every microsoft internet explorer deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2013-3893 yet — track the microsoft internet explorer advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2013-3893 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.