CVE-2021-3391

MEDIUMNVD 5.35.3—

5.3

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

CVSS v3: 5.3
EG Score: 5.3(medium)
EPSS: 58.6%
KEV: Not listed

Published

March 29, 2021

Last Modified

November 21, 2024

References (6)

cve@mitrehttps://github.com/optiv/rustyIron
cve@mitrehttps://www.mobileiron.com/en/blog/mobileiron-security-updates-available
cve@mitrehttps://www.optiv.com/explore-optiv-insights/source-zero/mobileiron-mdm-contains-static-key-allowing-account-enumeration
af854a3a-2127-422b-91ae-364da2661108https://github.com/optiv/rustyIron
af854a3a-2127-422b-91ae-364da2661108https://www.mobileiron.com/en/blog/mobileiron-security-updates-available
af854a3a-2127-422b-91ae-364da2661108https://www.optiv.com/explore-optiv-insights/source-zero/mobileiron-mdm-contains-static-key-allowing-account-enumeration

Data Freshness Timeline

(refreshed 11× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-29 13:42 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-3391?

CVE-2021-3391 is a medium vulnerability published on March 29, 2021. 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

When was CVE-2021-3391 disclosed?

CVE-2021-3391 was first published in the National Vulnerability Database on March 29, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-3391 actively exploited?

CVE-2021-3391 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 58.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-3391?

CVE-2021-3391 has a CVSS v3 base score of 5.3 (NVD).

How do I remediate CVE-2021-3391?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-3391, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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CVE-2021-3391

📅 Published

🔄 Last Modified

🔗 References (6)