JscriptApplication · Microsoft

CVE-2011-0663

HIGH · 8.8 CVSS v3.1 Published 2011-04-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Multiple integer overflows in the Microsoft (1) JScript 5.6 through 5.8 and (2) VBScript 5.6 through 5.8 scripting engines allow remote attackers to execute arbitrary code via a crafted web page, aka "Scripting Memory Reallocation Vulnerability."

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Integer overflow vulnerabilities exist in the memory reallocation functions of Microsoft JScript 5.6-5.8 and VBScript 5.6-5.8 scripting engines. When processing specially crafted web pages, these overflows allow attackers to corrupt memory and execute arbitrary code remotely.

MitigationDeploy the relevant Microsoft security update (MS11-031) to affected Windows systems, prioritizing internet-facing machines and systems running older Windows versions that include these scripting engines.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JscriptApplication
Affected:= 5.6= 5.7= 5.8
VbscriptApplication
Affected:= 5.6= 5.7= 5.8

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check JScript version on the system
    Create a .js file containing 'WScript.Echo("JScript Version: " + ScriptEngineMajorVersion + "." + ScriptEngineMinorVersion + "." + ScriptEngineBuildVersion);' and execute it with cscript.exe or wscript.exe, or check the jscript.dll file version in %SystemRoot%\System32\jscript.dll using PowerShell: (Get-Item C:\Windows\System32\jscript.dll).VersionInfo.FileVersion
    Affected if The reported version matches 5.6, 5.7, or 5.8 indicating the installed JScript engine is vulnerable
  2. Check VBScript version on the system
    Create a .vbs file containing 'WScript.Echo("VBScript Version: " & ScriptEngineMajorVersion & "." & ScriptEngineMinorVersion & "." & ScriptEngineBuildVersion)' and execute it with cscript.exe or wscript.exe, or check the vbscript.dll file version in %SystemRoot%\System32\vbscript.dll using PowerShell: (Get-Item C:\Windows\System32\vbscript.dll).VersionInfo.FileVersion
    Affected if The reported version matches 5.6, 5.7, or 5.8 indicating the installed VBScript engine is vulnerable
  3. Determine if JScript or VBScript are actively used
    Check for the presence of jscript.dll or vbscript.dll in System32, and review installed software for Internet Explorer or Windows Script Host installations. Query installed Windows features via 'Get-WindowsOptionalFeature -Online' or check for IE/WSH in the system
    Affected if Either scripting engine is installed and the versions from steps 1 or 2 match the vulnerable 5.6-5.8 range

If either JScript or VBScript versions 5.6, 5.7, or 5.8 are installed on the system, the environment is affected by this CVE.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Deploy the relevant Microsoft security update (MS11-031) to affected Windows systems, prioritizing internet-facing machines and systems running older Windows versions that include these scripting engines.

Fix this in Jscript Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2011-0663 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2011-0663 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data