Cyber Resilience

CVE-2021-43448

MediumPublic PoC

Published: 23 January 2023

Published
23 January 2023
Modified
02 April 2025
KEV Added
Patch
CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS Score 0.0036 58.7th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43448 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Onlyoffice Server. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 41.3% 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

ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Improper Input Validation. A lack of input validation can allow an attacker to spoof the names of users who interact with a document, if the document id is known.

CWE(s)

Related Threats

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

Affected Assets

onlyoffice
server
≤ 7.0.0.49

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.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References