Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-20208

22
FAUCET Score

CVE-2021-20208 is a flaw in cifs-utils versions prior to 6.13, allowing a user within a container to leverage host Kerberos credentials when mounting a krb5 CIFS filesystem. This vulnerability primarily impacts data confidentiality and integrity across various Fedora, Red Hat Enterprise Linux, and Samba cifs-utils products. Rated Medium severity with a CVSS score of 6.1, it requires local access and high attack complexity, but could lead to significant data compromise. There is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
>= 4.0, < 6.13CPE matchmatch criteria
cpe:2.3:a:samba:cifs-utils:*:*:*:*:*:*:*:*
7.0CPE matchmatch criteria
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
8.0CPE matchmatch criteria
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
34CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.1MEDIUM

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

Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
0.8
Impact Score
4.7
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.64%
Probability of exploitation in next 30 days
EPSS Percentile
47.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0064 is in the 95th percentile among its peer group of 296 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.0 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (10)

microsoftpatch availablevia msrc
Product: cbl2 cifs-utils 6.8-6 on CBL Mariner 2.0Fixed in: 6.8-6
microsoftpatch availablevia msrc
Product: 19062-16823Fixed in: 6.8-6
microsoftpatch availablevia msrc
Product: cm1 cifs-utils 6.8-5 on CBL Mariner 1.0Fixed in: 6.8-5
microsoftpatch availablevia msrc
Product: 19061-16820Fixed in: 6.8-5
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 x64Fixed in: 6.8-5
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 ARMFixed in: 6.8-5
microsoftpatch availablevia msrc
Product: CBL Mariner 2.0 x64Fixed in: 6.8-6
microsoftpatch availablevia msrc
Product: CBL Mariner 2.0 ARMFixed in: 6.8-6
redhatno patchvia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: cifs-utils
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: cifs-utils

Vendor Advisories (3)

microsoft2023-Mar/CVE-2021-20208

CVE-2021-20208

Mar 14, 2023
microsoft2021-Apr/CVE-2021-20208Moderate

A flaw was found in cifs-utils in versions before 6.13. A user when mounting a krb5 CIFS file system from within a container can use Kerberos credentials of the host. The highest threat from this vulnerability is to data confidentiality and integrity.

Apr 13, 2021
redhatCVE-2021-20208Moderate

cifs-utils: Container can use kerberos cache from the host via mount.cifs/cifs.upcall

Apr 12, 2021

References

bugzilla.redhat.com / show_bug.cgi
Issue TrackingThird Party Advisory
bugzilla.samba.org / show_bug.cgi
Issue TrackingPatchVendor Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/2W4HSDIWXXNQBUW5ZS37RQMLJ7THK5AS
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/66WJ3SVBHCSNQZAWSGLB6FBOCFU45FFG
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/Z4BZSJXROEFHYATAAHHRR6P3HUSMPQB3