CVE-2009-3103

CVE-2009-3103 is a critical-severity vulnerability in Microsoft Windows Server 2008 with a CVSS 2.0 base score of 10.0. Its EPSS exploit-prediction score of 90% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-399.

Key facts

Description

Array index error in the SMBv2 protocol implementation in srv2.sys in Microsoft Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold and SP2, and Windows 7 RC allows remote attackers to execute arbitrary code or cause a denial of service (system crash) via an & (ampersand) character in a Process ID High header field in a NEGOTIATE PROTOCOL REQUEST packet, which triggers an attempted dereference of an out-of-bounds memory location, aka "SMBv2 Negotiation Vulnerability." NOTE: some of these details are obtained from third party information.

Frequently asked questions

What is CVE-2009-3103?
Array index error in the SMBv2 protocol implementation in srv2.sys in Microsoft Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold and SP2, and Windows 7 RC allows remote attackers to execute arbitrary code or cause a denial of service (system crash) via an & (ampersand) character in a Process ID High header field in a NEGOTIATE PROTOCOL REQUEST packet, which triggers an attempted dereference of an out-of-bounds memory location, aka "SMBv2 Negotiation Vulnerability." NOTE: some of these details are obtained from third party information.
How severe is CVE-2009-3103?
CVE-2009-3103 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-2009-3103 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 90% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3103?
CVE-2009-3103 primarily affects Microsoft Windows Server 2008. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3103?
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-2009-3103 published?
CVE-2009-3103 was published on 2009-09-08 and last updated on 2026-06-16.

References

Affected products (10)

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