What is the CVSS score of CVE-2013-3893?

CVE-2013-3893 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 81.2%.

Is there a public PoC exploit available for CVE-2013-3893?

Yes, a public proof-of-concept exploit is available for CVE-2013-3893. Prioritise patching immediately. EPSS: 81.2%.

How to fix or mitigate CVE-2013-3893?

Within 24 hours: Identify all affected systems running the SetMouseCapture implementation in mshtml.dll in Microsof and apply vendor patches immediately. Monitor vendor channels for patch availability.

Microsoft CVE-2013-3893

HIGH

Resource Management Errors (CWE-399)

2013-09-18 secure@microsoft.com

RCE Microsoft

8.8

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-399 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V14 - Configuration Dependency management, component inventory
Impact	High risk. The exploit affected all IE versions (6-11) and demonstrated a creative ASLR bypass technique. Attributed to the APT group DeputyDog, targeting Japanese organizations.
Exploit ScenarioDerived	A compromised Japanese media website served an IE exploit that triggered the SetMouseCapture UAF. The exploit used ms-help: URLs to load the non-ASLR hxds.dll for reliable exploitation, then installed the DeputyDog/Hydraq implant for espionage operations.

Act Now Prioritize within 24-48h. Why: HIGH severity + EPSS > 10%.

Exploited in the wild (CISA KEV) No patch listed yet 81.2% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 26, 2026

Internet Explorer 6 through 11 contain a use-after-free vulnerability in the SetMouseCapture implementation that allows remote code execution through crafted JavaScript, exploited in targeted attacks via ms-help: URL protocol.

Earlier versions of this analysis (1)

v1 Mar 26, 2026 - 11:18 CVSS 8.8

A use-after-free in IE's mshtml.dll SetMouseCapture implementation enables remote code execution through crafted JavaScript. The exploit leveraged ms-help: URLs to load hxds.dll for ASLR bypass, exploited as a zero-day in September 2013.

RemediationAI

Apply Microsoft security update MS13-080. Disable the ms-help: URL protocol handler. Deploy EMET or Windows Defender Exploit Guard with forced ASLR.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The CWE-399 use-after-free occurs in the mouse capture subsystem of mshtml.dll. Attackers used crafted JavaScript strings to trigger the free and reuse cycle. The innovative exploitation technique used ms-help: protocol URLs to load hxds.dll, a non-ASLR module, providing predictable gadget addresses for ROP chains.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.8 HIGH

AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Added to CISA KEV

Oct 22, 2025 - 01:15 cisa

CISA KEV

PoC Detected

Oct 22, 2025 - 01:15 vuln.today

Public exploit code

CVE Published

Sep 18, 2013 - 10:08 nvd

HIGH 8.8

DescriptionCVE.org

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.

Executive ViewAI

Why It Matters

CVE-2013-3893 presents significant security risk rated CVSS 8.8. Successful exploitation could significantly impact the confidentiality, integrity, or availability of affected systems. This vulnerability is actively exploited in the wild (KEV-listed) and requires immediate remediation. Immediate patching is required per CISA KEV mandate.

Business Impact: Severe

Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Implement network-level access controls to limit exposure; (2) Enable enhanced monitoring and alerting; (3) Apply principle of least privilege.

Threat Intelligence Overview

Threat Score

9.2/10

Composite threat intelligence

EPSS Score

81.2%

Top 1% exploitable

Threat Intel

1 sources

Exploit

POC

Public exploit code exists

Data Quality

8 sources

Confidence: High

NVD

CVE.org

CISA KEV

EPSS POC (1) THREAT

Exploit-DB

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV Yes

Public POC Yes

EPSS 81.2%

Patch available No

Active threat Yes

Deciding rule

HIGH severity + EPSS > 10%

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.