CVE-2002-1978: IPFilter 3.1.1 through 3.4.28 allows remote attackers to bypass firewall rules by sending a PASV command strin

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HIGH 7.5DOWNGRADE

CVE-2002-1978 is a high-severity flaw (CVSS 7.5) affecting ipfilter. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IPFilter 3.1.1 through 3.4.28 allows remote attackers to bypass firewall rules by sending a PASV command string as the argument of another command to an FTP server, which generates a response that contains the string, causing IPFilter to treat the response as if it were a legitimate PASV command from the server.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	2.0% (top 19%)
CISA exploited list	No
Weakness	CWE-264
Published	2002-12-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: darren reed

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2002-12-31 05:00 UTCPublished CVE record published
2026-06-16 22:00 UTCUpdated Record last modified

darren reed ipfilter DOWNGRADE

Affected: 3.1.1 · 3.1.2 · 3.1.3 · 3.1.4 · 3.1.5 · 3.1.6 · 3.1.7 · 3.1.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.1.1

1. Check installed version

apt-cache policy ipfilter || rpm -q ipfilter || ipfilter --version

2. No fixed release: DOWNGRADE to a release before 3.1.1 (Debian / Ubuntu)

apt-cache madison ipfilter sudo apt install ipfilter=<VERSION_BEFORE_3.1.1> sudo apt-mark hold ipfilter

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list ipfilter sudo dnf downgrade ipfilter-<VERSION_BEFORE_3.1.1> sudo dnf versionlock add ipfilter

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2002-1978?

ipfilter: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2002-1978 being exploited?

CVE-2002-1978 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2002-1978 affect?

CVE-2002-1978 affects ipfilter. Severity is 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 argument of another command to an FTP server, which generates a response that contains the string, causing IPFilter to tr

How urgent is CVE-2002-1978?

Priority 46/100. High severity

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References

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