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Internet ExplorerApplication · Microsoft

CVE-2012-2523

HIGH · 9.3 CVSS v2.0 Published 2012-08-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
Integer overflow in Microsoft Internet Explorer 8 and 9, JScript 5.8, and VBScript 5.8 on 64-bit platforms allows remote attackers to execute arbitrary code by leveraging an incorrect size calculation during object copying, aka "JavaScript Integer Overflow Remote Code Execution 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 vulnerability in Microsoft Internet Explorer 8/9, JScript 5.8, and VBScript 5.8 on 64-bit platforms allows remote attackers to execute arbitrary code via incorrect size calculation during object copying operations in the JavaScript/VBScript engine.

MitigationApply Microsoft security updates for this vulnerability; consider migrating from deprecated Internet Explorer to modern browsers and removing legacy JScript/VBScript dependencies where possible.

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
Internet ExplorerApplication
Affected:= 8= 9
JscriptApplication
Affected:= 5.8
VbscriptApplication
Affected:= 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
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:M/Au:N/C:C/I:C/A:C

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. Verify system architecture is 64-bit
    Open Command Prompt and run 'systeminfo | findstr /C:"System Type"' or check System Properties. The value will show 'x64-based PC' for 64-bit systems.
    Affected if System is NOT 64-bit - the vulnerability only affects 64-bit platforms
  2. Determine Internet Explorer version
    Open IE, click Help > About Internet Explorer, or run 'iexplore.exe' and check the version in the title bar. Alternatively, check the file version of C:\Program Files\Internet Explorer\iexplore.exe
    Affected if Version is 8 or 9 on a 64-bit system - these versions are affected
  3. Check JScript version
    Open Command Prompt and run 'cscript //Nologo //E:jscript //Job:version' or check the file version of C:\Windows\System32\jscript.dll
    Affected if Version is 5.8.x on a 64-bit system - JScript 5.8 is affected
  4. Check VBScript version
    Open Command Prompt and run 'cscript //Nologo //E:vbscript //Job:version' or check the file version of C:\Windows\System32\vbscript.dll
    Affected if Version is 5.8.x on a 64-bit system - VBScript 5.8 is affected

A system is affected if it runs 64-bit Windows with Internet Explorer 8 or 9, or JScript 5.8, or VBScript 5.8 installed.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Microsoft security updates for this vulnerability; consider migrating from deprecated Internet Explorer to modern browsers and removing legacy JScript/VBScript dependencies where possible.

Recommended fix High confidence

Internet Explorer 10 or later (or Microsoft Edge for Windows 10+); JScript/VBScript updates via Windows Update

  1. Apply Microsoft security update MS12-023 (Cumulative Security Update for Internet Explorer) or subsequent IE cumulative updates to address the integer overflow vulnerability
  2. Upgrade Internet Explorer from version 8 or 9 to the latest version available for your Windows platform (Internet Explorer 11 or Microsoft Edge for supported Windows versions)
  3. Verify the installation of the security update by checking Windows Update > View update history
  4. Restart the system after applying updates
Caveat Older IE versions (8/9) may be required for legacy application compatibility; test web applications after upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Internet Explorer Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

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dbcve dependency scanner

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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-2012-2523 in production — separate from our analysis above.

No notes yet

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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