Security readout for executives and security teams
Plain-English summary
CVE-2021-43448 affects ONLYOFFICE as described in the CVE record. If an attacker knows a document ID, they may spoof the displayed names of users interacting with that document. This is primarily an integrity and trust issue for collaboration workflows, not a confidentiality or availability flaw based on the supplied CVSS data.
Executive priority
Treat this as a moderate-priority integrity issue for teams relying on ONLYOFFICE collaboration identity or audit trails. Prioritize validation if document links are broadly shared or if document activity attribution supports legal, financial, or operational decisions.
Technical view
The CVE describes CWE-20 improper input validation in ONLYOFFICE all versions as of 2021-11-08. The vector is network-reachable, high complexity, no privileges required, and requires user interaction. The stated impact is high integrity impact through user-name spoofing when a document ID is known.
Likely exposure
Exposure is most relevant to organizations using ONLYOFFICE document collaboration where document IDs are knowable through links, integrations, logs, or shared workflows. The source bundle does not provide CPEs, affected editions, or fixed version details.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Public references include a Nettitude research post about ONLYOFFICE WebSockets, but the provided CVE description only supports user-name spoofing tied to known document IDs.
Researcher notes
Evidence is limited: the affected CPE fields are empty, and no patch version is named. The CVSS vector indicates no privileges, high attack complexity, required user interaction, and high integrity impact. Avoid expanding the finding beyond spoofed collaborator names unless additional vendor evidence supports it.
Mitigation direction
- Check ONLYOFFICE vendor guidance for fixed versions or official workarounds.
- Restrict document access to trusted authenticated users wherever operationally possible.
- Reduce exposure of document IDs in links, logs, tickets, and integrations.
- Do not treat displayed collaborator names as sole audit evidence.
- Monitor vendor release notes for remediation specific to CVE-2021-43448.
Validation and detection
- Inventory ONLYOFFICE deployments and versions in the environment.
- Confirm whether exposed workflows reveal or reuse document IDs.
- Review collaboration audit trails for inconsistent or unexpected displayed user names.
- Check vendor advisories for any fixed version not present in the bundle.
- Verify compensating controls around document sharing and access restrictions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-43448 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N1.63.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/ONLYOFFICE/serverCVE reference
- https://www.onlyoffice.com/CVE reference
- https://labs.nettitude.com/blog/exploiting-onlyoffice-web-sockets-for-unauthenticated-remote-code-execution/CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.