CVE-2009-1923Windows 2000 Memory Corruption
Heap-based buffer overflow in the Windows Internet Name Service (WINS) component for Microsoft Windows 2000 SP4 and Server 2003 SP2 allows remote attackers to execute arbitrary code via a crafted WINS replication packet that triggers an incorrect buffer-length calculation, aka…
Published Aug 12, 2009 · Updated Apr 22, 2026
Key Facts
Patch immediately- CVE-2009-1923 is a critical-severity vulnerability (CVSS 9.3 v2) affecting Windows 2000 (Microsoft), Windows 2003 Server (Microsoft).
- It is exploited in the wild, listed in Industry KEV feed since Aug 18, 2009. No public exploit code is known.
- EPSS estimates a 25% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v2
9.3
AV:N/AC:M/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
25%
Higher than 97.8% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
47/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Aug 18, 2009
6 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
1
Reports of active use
Description
Heap-based buffer overflow in the Windows Internet Name Service (WINS) component for Microsoft Windows 2000 SP4 and Server 2003 SP2 allows remote attackers to execute arbitrary code via a crafted WINS replication packet that triggers an incorrect buffer-length calculation, aka "WINS Heap Overflow Vulnerability."
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Aug 18, 2009 | n/a | Not reported |
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 2000Microsoft | See advisory | n/a |
| Windows 2003 ServerMicrosoft | See advisory | n/a |
Timeline
Publicly disclosed
Aug 12, 2009
Added to Industry KEV feed
Aug 18, 2009
Last updated
Apr 22, 2026
Weakness Type
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
References
- exploitVulnCheck exploitation report
- otherMS09-039
- otheroval:org.mitre.oval:def:6410
- otherTA09-223A
FAQ
Common Questions.
Heap-based buffer overflow in the Windows Internet Name Service (WINS) component for Microsoft Windows 2000 SP4 and Server 2003 SP2 allows remote attackers to execute arbitrary code via a crafted WINS replication packet that triggers an incorrect buffer-length calculation, aka "WINS Heap Overflow Vulnerability."
Affected: Windows 2000 (Microsoft); Windows 2003 Server (Microsoft). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Aug 18, 2009.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2009-1923 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
Request A Demo