Security readout for executives and security teams
Plain-English summary
This CVE affects ONLYOFFICE deployments that used a weak default URL signing key as of November 8, 2021. An unauthenticated network attacker could forge signed document download URLs, undermining access control. The record does not show confirmed active exploitation or a named vendor fix.
Executive priority
Handle as a high-priority exposure review for any ONLYOFFICE deployment, especially external-facing services. The main business risk is bypassed document access control through forged signed URLs. Urgency is elevated by unauthenticated network reachability, but evidence of active exploitation is not provided.
Technical view
CVE-2021-43444 is an incorrect access control issue, mapped to CWE-287. The source bundle says signed document download URLs can be forged because the default URL signing key is weak. CVSS 3.1 is 7.5, with network access, low complexity, no privileges, no user interaction, and high integrity impact.
Likely exposure
Organizations running ONLYOFFICE versions present as of 2021-11-08 are potentially exposed, especially internet-facing document services or deployments retaining default signing secrets. The source data does not provide precise product editions, CPEs, fixed versions, or deployment prerequisites.
Exploitation context
The CVE is not listed in KEV, and the provided bundle does not confirm active exploitation. The cited Nettitude research is exploit-oriented, but the bundle alone does not establish broad in-the-wild abuse. Treat internet-facing instances as higher priority because the CVSS vector is unauthenticated network exploitable.
Researcher notes
The source bundle is sparse: affected CPEs, fixed versions, and official remediation details are absent. The strongest grounded facts are the weak default URL signing key, unauthenticated network attack conditions, and high CVSS integrity impact. Validate configuration and version details against current ONLYOFFICE guidance before closing risk.
Mitigation direction
- Review ONLYOFFICE vendor guidance for fixed versions or configuration updates.
- Replace any default or weak URL signing key with a strong unique secret.
- Restrict public access to ONLYOFFICE services where business workflows allow.
- Monitor document URL and download activity for unexpected access patterns.
- Prioritize remediation for internet-facing or multi-tenant deployments.
Validation and detection
- Inventory all ONLYOFFICE deployments and identify versions active around 2021-11-08.
- Review configuration for default or weak URL signing secrets.
- Confirm signed document URLs are rejected when signatures are invalid.
- Check access logs for anomalous document download URL activity.
- Verify whether vendor advisories name a fixed version for your edition.
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-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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-2021-43444 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.