CVE-2021-3391

Name: CVE-2021-3391
Creator: NVD / NIST
Published: 2021-03-29T20:15:13.533+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.15%

Last modified Jun 17, 2026

CVE-2021-3391 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. MobileIron Mobile@Work through 2021-03-22 allows attackers to distinguish among valid, disabled, and nonexistent user accounts by observing the number of failed login attempts needed to produce a Lockout error message. EPSS estimates a 1.15% chance of exploitation in the next 30 days.

Description

MobileIron Mobile@Work through 2021-03-22 allows attackers to distinguish among valid, disabled, and nonexistent user accounts by observing the number of failed login attempts needed to produce a Lockout error message

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

1.15%

62.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Mobileiron	Mobile\@Work	<= 11.0.0.0.115r
Mobileiron	Mobile\@Work	<= 12.11.1

References

https://github.com/optiv/rustyIronThird Party Advisory
https://www.mobileiron.com/en/blog/mobileiron-security-updates-availableNot Applicable
https://www.optiv.com/explore-optiv-insights/source-zero/mobileiron-mdm-contains-static-key-allowing-account-enumerationTechnical Description, Third Party Advisory
https://github.com/optiv/rustyIronThird Party Advisory
https://www.mobileiron.com/en/blog/mobileiron-security-updates-availableNot Applicable
https://www.optiv.com/explore-optiv-insights/source-zero/mobileiron-mdm-contains-static-key-allowing-account-enumerationTechnical Description, Third Party Advisory

Timeline

Published: Mar 29, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3391?

How severe is CVE-2021-3391?

CVE-2021-3391 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.15% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3391?

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-2021-3391?

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

Scan your code now

Source: NVD / NIST