CVE-2021-39251

Name: CVE-2021-39251
Creator: NVD / NIST
Published: 2021-09-07T15:15:07.81+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.39%

Last modified Jun 17, 2026

CVE-2021-39251 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. A crafted NTFS image can cause a NULL pointer dereference in ntfs_extent_inode_open in NTFS-3G < 2021.8.22.. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

A crafted NTFS image can cause a NULL pointer dereference in ntfs_extent_inode_open in NTFS-3G < 2021.8.22.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.39%

30.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Tuxera	Ntfs-3g	< 2021.8.22
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0
Fedoraproject	Fedora	33
Fedoraproject	Fedora	35

References

http://www.openwall.com/lists/oss-security/2021/08/30/1Mailing List, Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988386Issue Tracking, Mailing List, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2001649Issue Tracking, Third Party Advisory
https://github.com/tuxera/ntfs-3g/releasesRelease Notes, Third Party Advisory
https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-q759-8j5v-q5jpThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00013.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/766ISTT3KCARKFUIQT7N6WV6T63XOKG3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HSEKTKHO5HFZHWZNJNBJZA56472KRUZI/
https://security.gentoo.org/glsa/202301-01Third Party Advisory
https://www.debian.org/security/2021/dsa-4971Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/30/1Mailing List, Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988386Issue Tracking, Mailing List, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2001649Issue Tracking, Third Party Advisory
https://github.com/tuxera/ntfs-3g/releasesRelease Notes, Third Party Advisory
https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-q759-8j5v-q5jpThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00013.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/766ISTT3KCARKFUIQT7N6WV6T63XOKG3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HSEKTKHO5HFZHWZNJNBJZA56472KRUZI/
https://security.gentoo.org/glsa/202301-01Third Party Advisory
https://www.debian.org/security/2021/dsa-4971Third Party Advisory

Timeline

Published: Sep 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-39251?

A crafted NTFS image can cause a NULL pointer dereference in ntfs_extent_inode_open in NTFS-3G < 2021.8.22.

How severe is CVE-2021-39251?

CVE-2021-39251 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2021-39251?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-39251?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST