CVE-2003-0709: Buffer overflow in the whois client, which is not setuid but is sometimes called from within CGI programs, may

This month

HIGH 7.5DOWNGRADE

CVE-2003-0709 is a high-severity flaw (CVSS 7.5) affecting whois. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the whois client, which is not setuid but is sometimes called from within CGI programs, may allow remote attackers to execute arbitrary code via a long command line option.

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	2.8% (top 14%)
CISA exploited list	No
Published	2003-10-20
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: whois

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

Am I affected?

Timeline

2003-10-20 04:00 UTCPublished CVE record published
2026-06-16 22:02 UTCUpdated Record last modified

whois whois DOWNGRADE

Affected: 4.5.7 · 4.6.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.5.7

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.5.7 (Debian / Ubuntu)

apt-cache madison whois sudo apt install whois=<VERSION_BEFORE_4.5.7> sudo apt-mark hold whois

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

dnf --showduplicates list whois sudo dnf downgrade whois-<VERSION_BEFORE_4.5.7> sudo dnf versionlock add whois

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-2003-0709?

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

Is CVE-2003-0709 being exploited?

CVE-2003-0709 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-2003-0709 affect?

CVE-2003-0709 affects whois. Severity is high (CVSS 7.5). Buffer overflow in the whois client, which is not setuid but is sometimes called from within CGI programs, may allow remote attackers to execute arbitrary code via a long command line option.

How urgent is CVE-2003-0709?

Priority 53/100. High severity; Public exploit reference

References

← Back to latest CVEs