CVE-2010-1734: The SfnINSTRING function in win32k.sys in the kernel in Microsoft Windows 2000, XP, and Server 2003 allows loc

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MEDIUM 4.9WATCHLISTMITIGATEMITIGATEMITIGATE

CVE-2010-1734 is a medium-severity flaw (CVSS 4.9) affecting windows 2000, windows 2003 server, windows server 2003. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The SfnINSTRING function in win32k.sys in the kernel in Microsoft Windows 2000, XP, and Server 2003 allows local users to cause a denial of service (system crash) via a 0x18d value in the second argument (aka the Msg argument) of a PostMessage function call for the DDEMLEvent window.

Why this priority

Public exploit reference
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.9 (Medium)
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-20
Published	2010-05-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: microsoft

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2010-05-06 12:47 UTCPublished CVE record published
2026-06-16 23:19 UTCUpdated Record last modified

microsoft windows 2000 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 2003 server MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows server 2003 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows xp MITIGATE

Affected: all versions · sp3 · sp3 unknown

Fixed in: no fixed release known

Safe to downgrade to: a release before sp3

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Microsoft Windows XP/2000/2003 - 'win32k.sys' SfnINSTRING Local kernel Denial of Service

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2010-1734?

windows 2000: mitigate or apply the listed mitigation; windows 2003 server: mitigate or apply the listed mitigation; windows server 2003: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2010-1734 being exploited?

CVE-2010-1734 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2010-1734 affect?

CVE-2010-1734 affects windows 2000, windows 2003 server, windows server 2003. Severity is medium (CVSS 4.9). The SfnINSTRING function in win32k.sys in the kernel in Microsoft Windows 2000, XP, and Server 2003 allows local users to cause a denial of service (system crash) via a 0x18d value in the second argument (aka the Msg argument) of a PostMess

How urgent is CVE-2010-1734?

Priority 49/100. Public exploit reference; On your watchlist

Software pages

Windows vulnerabilities · Windows Server vulnerabilities

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References

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