How severe is CVE-2009-2523?

CVE-2009-2523 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2009-2523 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-2523?

CVE-2009-2523 affects Microsoft Windows 2000. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2009-2523?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2009-2523 published?

CVE-2009-2523 was published on 2009-11-11 and last updated on 2026-06-16.

CVE-2009-2523

CVE-2009-2523 is a critical-severity vulnerability in Microsoft Windows 2000 with a CVSS 2.0 base score of 10.0. Its EPSS exploit-prediction score of 26% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-125.

Key facts

Severity: Critical (CVSS 2.0 base score 10.0)
EPSS exploit prediction: 26% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Microsoft Windows 2000
Published: 2009-11-11
Last modified: 2026-06-16

Description

The License Logging Server (llssrv.exe) in Microsoft Windows 2000 SP4 allows remote attackers to execute arbitrary code via an RPC message containing a string without a null terminator, which triggers a heap-based buffer overflow in the LlsrLicenseRequestW method, aka "License Logging Server Heap Overflow Vulnerability."

Frequently asked questions

What is CVE-2009-2523?: The License Logging Server (llssrv.exe) in Microsoft Windows 2000 SP4 allows remote attackers to execute arbitrary code via an RPC message containing a string without a null terminator, which triggers a heap-based buffer overflow in the LlsrLicenseRequestW method, aka "License Logging Server Heap Overflow Vulnerability."
How severe is CVE-2009-2523?: CVE-2009-2523 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-2009-2523 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2523?: CVE-2009-2523 affects Microsoft Windows 2000. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2009-2523?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2009-2523 published?: CVE-2009-2523 was published on 2009-11-11 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:o:microsoft:windows_2000:*:sp4:*:*:*:*:*:*

More vulnerabilities in Microsoft Windows 2000

CVE-2010-0269 — Critical (CVSS 10.0): The SMB client in Microsoft Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold, SP1,…
CVE-2010-0231 — Critical (CVSS 10.0): The SMB implementation in the Server service in Microsoft Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003…
CVE-2009-3677 — Critical (CVSS 10.0): The Internet Authentication Service (IAS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold…
CVE-2009-1925 — Critical (CVSS 10.0): The TCP/IP implementation in Microsoft Windows Vista Gold, SP1, and SP2 and Server 2008 Gold and SP2 does not properly…
CVE-2009-1930 — Critical (CVSS 10.0): The Telnet service in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold, SP1, and SP2, and Server…
CVE-2009-1138 — Critical (CVSS 10.0): The LDAP service in Active Directory on Microsoft Windows 2000 SP4 does not properly free memory for LDAP and LDAPS…

All CVEs affecting Microsoft Windows 2000 →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →