CVE-2021-42757

MEDIUMNVD 6.76.7—Trending — 3 sources updated this week

6.7

A buffer overflow [CWE-121] in the TFTP client library of FortiOS before 6.4.7 and FortiOS 7.0.0 through 7.0.2, may allow an authenticated local attacker to achieve arbitrary code execution via specially crafted command line arguments.

CVSS v3: 6.7
EG Score: 6.7(medium)
EPSS: 22.2%
KEV: Not listed

Published

December 8, 2021

Last Modified

October 16, 2025

References (2)

psirt@fortinethttps://fortiguard.com/advisory/FG-IR-21-173
af854a3a-2127-422b-91ae-364da2661108https://fortiguard.com/advisory/FG-IR-21-173

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

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

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 06:45 UTCEG score recompute
2026-05-26 06:45 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-42757?

CVE-2021-42757 is a medium vulnerability published on December 8, 2021. A buffer overflow [CWE-121] in the TFTP client library of FortiOS before 6.4.7 and FortiOS 7.0.0 through 7.0.2, may allow an authenticated local attacker to achieve arbitrary code execution via specially crafted command line arguments.

When was CVE-2021-42757 disclosed?

CVE-2021-42757 was first published in the National Vulnerability Database on December 8, 2021, with the most recent update on October 16, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-42757 actively exploited?

CVE-2021-42757 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-42757?

CVE-2021-42757 has a CVSS v3 base score of 6.7 (NVD).

How do I remediate CVE-2021-42757?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42757, 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.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-42757

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CVE-2021-42757

📅 Published

🔄 Last Modified

🔗 References (2)