How severe is CVE-1999-0511?

CVE-1999-0511 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-1999-0511 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0511?

CVE-1999-0511 primarily affects Microsoft Windows 2000. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-0511?

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-1999-0511 published?

CVE-1999-0511 was published on 1997-01-01 and last updated on 2026-06-16.

CVE-1999-0511

CVE-1999-0511 is a critical-severity vulnerability in Microsoft Windows 2000 with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 7.5
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Microsoft Windows 2000
Published: 1997-01-01
Last modified: 2026-06-16

Description

IP forwarding is enabled on a machine which is not a router or firewall.

Frequently asked questions

What is CVE-1999-0511?: IP forwarding is enabled on a machine which is not a router or firewall.
How severe is CVE-1999-0511?: CVE-1999-0511 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-1999-0511 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0511?: CVE-1999-0511 primarily affects Microsoft Windows 2000. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-0511?: 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-1999-0511 published?: CVE-1999-0511 was published on 1997-01-01 and last updated on 2026-06-16.

References

https://www.cve.org/CVERecord?id=CVE-1999-0511

Affected products (2)

cpe:2.3:o:microsoft:windows_2000:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_nt:*:*:*:*:*:*:*:*

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