CVE-2001-0971: Directory traversal vulnerability in ACI 4d webserver allows remote attackers to read arbitrary files via a .

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MEDIUM 5.0DOWNGRADE

CVE-2001-0971 is a medium-severity flaw (CVSS 5.0) affecting 4d webserver. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Directory traversal vulnerability in ACI 4d webserver allows remote attackers to read arbitrary files via a .. (dot dot) or drive letter (e.g., C:) in an HTTP request.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.2% (top 18%)
CISA exploited list	No
Published	2001-08-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: aci

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

Am I affected?

Timeline

2001-08-31 04:00 UTCPublished CVE record published
2026-06-16 21:55 UTCUpdated Record last modified

aci 4d webserver DOWNGRADE

Affected: 6.5.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.5.7

1. Check installed version

apt-cache policy 4d-webserver || rpm -q 4d-webserver || 4d-webserver --version

2. No fixed release: DOWNGRADE to a release before 6.5.7 (Debian / Ubuntu)

apt-cache madison 4d-webserver sudo apt install 4d-webserver=<VERSION_BEFORE_6.5.7> sudo apt-mark hold 4d-webserver

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

dnf --showduplicates list 4d-webserver sudo dnf downgrade 4d-webserver-<VERSION_BEFORE_6.5.7> sudo dnf versionlock add 4d-webserver

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-2001-0971?

4d webserver: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2001-0971 being exploited?

CVE-2001-0971 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-2001-0971 affect?

CVE-2001-0971 affects 4d webserver. Severity is medium (CVSS 5.0). Directory traversal vulnerability in ACI 4d webserver allows remote attackers to read arbitrary files via a .. (dot dot) or drive letter (e.g., C:) in an HTTP request.

How urgent is CVE-2001-0971?

Priority 43/100. Public exploit reference

Related CVEs

CVE-2002-0966 HIGH 7.5 DOWNGRADE Buffer overflow in 4D web server 6.7.3 allow remote attackers to cause a denial of service and possibly execut
CVE-2002-0578 HIGH 7.5 DOWNGRADE Buffer overflow in 4D WebServer 6.7.3 allows remote attackers to cause a denial of service and possibly execut

References

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