dbcve.org
Diskstation ManagerOperating system · Synology

CVE-2021-43926

CRITICAL · 9.8 CVSS v3.1 Published 2022-02-07
Fix available
A fix is available. Upgrade to 6.2.4-25556-3 / 7.0.1-42218-2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper neutralization of special elements used in an SQL command ('SQL Injection') vulnerability in Log Management functionality in Synology DiskStation Manager (DSM) before 7.0.1-42218-2 allows remote attackers to inject SQL commands via unspecified vectors.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

SQL injection vulnerability in Synology DSM's Log Management functionality allows remote attackers to inject arbitrary SQL commands. This is a critical pre-authentication flaw in the web interface, enabling complete database compromise without credentials.

MitigationUpgrade Synology DSM to version 7.0.1-42218-2 or later. If immediate patching is not possible, restrict network access to the management interface using firewall rules or VPN.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Diskstation ManagerOperating system
Affected:>= 6.2, < 6.2.4-25556-3>= 7.0, < 7.0.1-42218-2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Synology DSM version
    Access the web interface and navigate to Control Panel > Info Center > Info, or via SSH run: cat /etc/VERSION
    Affected if The displayed version falls within 6.2.x before 6.2.4-25556-3, or 7.0.x before 7.0.1-42218-2
  2. Verify the Log Management module is accessible
    Check if the web interface is accessible at the default HTTP/HTTPS ports (5000/5001) and confirm the Log Center or Log Management feature is enabled in Control Panel
    Affected if The Log Management feature is enabled and accessible without authentication restrictions
  3. Confirm network exposure of the management interface
    Review firewall rules or network configuration to determine if DSM web interface ports (5000, 5001) are exposed to untrusted networks or the public internet
    Affected if The DSM web interface is directly accessible from external networks without VPN or IP restrictions
  4. Check for recent authentication logs or SQL injection indicators
    Review system logs in Log Center for suspicious SQL syntax in query parameters, or check /var/log/messages and /var/log/synology for anomalous database query patterns
    Affected if Unexpected SQL syntax or malformed queries appear in logs targeting the log management interface
  5. Confirm the DSM build number
    Run synoget --version or check /etc/VERSION for the full build number including the -xxxxx suffix
    Affected if The build number is lower than 25556-3 for DSM 6.2, or lower than 42218-2 for DSM 7.0

You are affected if your DSM version is 6.2.x up to build 25555 or 7.0.x up to build 42217, and the Log Management web interface is accessible from your network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.2.4-25556-3 / 7.0.1-42218-2 or later
Fixed in 6.2.4-25556-37.0.1-42218-2
Interim mitigation

Upgrade Synology DSM to version 7.0.1-42218-2 or later. If immediate patching is not possible, restrict network access to the management interface using firewall rules or VPN.

Recommended fix High confidence

DSM 6.2.4-25556-3 or later; DSM 7.0.1-42218-2 or later

  1. 1. Identify current DSM version via Control Panel > System > System Information > General
  2. 2. If running DSM 6.2.x, plan upgrade to version 6.2.4-25556-3 or later
  3. 3. If running DSM 7.0.x, plan upgrade to version 7.0.1-42218-2 or later
  4. 4. Download the appropriate update from Synology Download Center or use Control Panel > Update & Restore
  5. 5. Apply the update during a maintenance window following Synology's standard upgrade procedure

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Diskstation Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-43926 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data