Cyber Resilience

CVE-2021-3199

CriticalPublic PoC

Published: 26 January 2021

Published
26 January 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0676 91.5th percentile
Risk Priority 24 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3199 is a critical-severity Path Traversal (CWE-22) vulnerability in Onlyoffice Document Server. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 8.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Directory traversal with remote code execution can occur in /upload in ONLYOFFICE Document Server before 5.6.3, when JWT is used, via a /.. sequence in an image upload parameter.

CWE(s)
CWE-22

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

onlyoffice
document server
≤ 5.6.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-10 Information Input Validation
addresses: CWE-22

Validates pathnames and filenames to prevent traversal outside intended directories.

References