CVE-2002-2251: Buffer overflow in the changevalue function in libcgi.h for Marcos Luiz Onisto Lib CGI 0.1 allows remote attac

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HIGH 10.0DOWNGRADE

CVE-2002-2251 is a high-severity flaw (CVSS 10.0) affecting lib cgi. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the changevalue function in libcgi.h for Marcos Luiz Onisto Lib CGI 0.1 allows remote attackers to execute arbitrary code via a long argument.

Why this priority

Critical severity
EPSS top 6%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	6.6% (top 6%)
CISA exploited list	No
Weakness	CWE-119
Published	2002-12-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: marcos luiz onisto

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

marcos luiz onisto lib cgi DOWNGRADE

Affected: 0.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.1

1. Check installed version

apt-cache policy lib-cgi || rpm -q lib-cgi || lib-cgi --version

2. No fixed release: DOWNGRADE to a release before 0.1 (Debian / Ubuntu)

apt-cache madison lib-cgi sudo apt install lib-cgi=<VERSION_BEFORE_0.1> sudo apt-mark hold lib-cgi

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

dnf --showduplicates list lib-cgi sudo dnf downgrade lib-cgi-<VERSION_BEFORE_0.1> sudo dnf versionlock add lib-cgi

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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Lib CGI 0.1 - Include Buffer Overflow

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-2002-2251?

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

Is CVE-2002-2251 being exploited?

CVE-2002-2251 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-2002-2251 affect?

CVE-2002-2251 affects lib cgi. Severity is high (CVSS 10.0). Buffer overflow in the changevalue function in libcgi.h for Marcos Luiz Onisto Lib CGI 0.1 allows remote attackers to execute arbitrary code via a long argument.

How urgent is CVE-2002-2251?

Priority 63/100. Critical severity; EPSS top 6%: very likely to be exploited; Public exploit reference

References

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