How severe is CVE-2001-0402?

CVE-2001-0402 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-2001-0402 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2001-0402?

CVE-2001-0402 primarily affects Darren Reed Ipfilter. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2001-0402?

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

When was CVE-2001-0402 published?

CVE-2001-0402 was published on 2001-06-18 and last updated on 2026-06-16.

CVE-2001-0402

CVE-2001-0402 is a high-severity vulnerability in Darren Reed Ipfilter with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Darren Reed Ipfilter
Published: 2001-06-18
Last modified: 2026-06-16

Description

IPFilter 3.4.16 and earlier does not include sufficient session information in its cache, which allows remote attackers to bypass access restrictions by sending fragmented packets to a restricted port after sending unfragmented packets to an unrestricted port.

Frequently asked questions

What is CVE-2001-0402?: IPFilter 3.4.16 and earlier does not include sufficient session information in its cache, which allows remote attackers to bypass access restrictions by sending fragmented packets to a restricted port after sending unfragmented packets to an unrestricted port.
How severe is CVE-2001-0402?: CVE-2001-0402 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-2001-0402 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2001-0402?: CVE-2001-0402 primarily affects Darren Reed Ipfilter. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2001-0402?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2001-0402 published?: CVE-2001-0402 was published on 2001-06-18 and last updated on 2026-06-16.

References

Affected products (3)

cpe:2.3:a:darren_reed:ipfilter:*:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*
cpe:2.3:o:openbsd:openbsd:2.8:*:*:*:*:*:*:*

More vulnerabilities in Darren Reed Ipfilter

CVE-2002-1978 — High (CVSS 7.5): IPFilter 3.1.1 through 3.4.28 allows remote attackers to bypass firewall rules by sending a PASV command string as the…
CVE-2009-1476 — High (CVSS 7.2): Buffer overflow in lib/load_http.c in ippool in Darren Reed IPFilter (aka IP Filter) 4.1.31 allows local users to gain…
CVE-1999-1244 — High (CVSS 7.2): IPFilter 3.2.3 through 3.2.10 allows local users to modify arbitrary files via a symlink attack on the saved output…
CVE-2000-0553 — Low (CVSS 2.6): Race condition in IPFilter firewall 3.4.3 and earlier, when configured with overlapping "return-rst" and "keep state"…

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