CVE-2020-27655
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 · uneditedImproper access control vulnerability in Synology Router Manager (SRM) before 1.2.4-8081 allows remote attackers to access restricted resources via inbound QuickConnect traffic.
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 confidenceSynology Router Manager (SRM) versions before 1.2.4-8081 contain an improper access control vulnerability that allows remote attackers to bypass authentication and access restricted administrative resources through inbound QuickConnect traffic, which is the default remote access mechanism.
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>= 1.2, < 1.2.4-8081CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 checksWork through these to decide whether this CVE applies to you.
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Identify installed SRM versionLog into the Synology Router Manager web interface and navigate to Control Panel > System > Update & Restore to view the current firmware version. Alternatively, run 'synoversion' or check '/etc.defaults/VERSION' via SSH.Affected if version is 1.2.x or later but earlier than 1.2.4-8081
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Confirm version range matches affected criteriaCompare your installed version number against the affected range: 1.2.0 through 1.2.3-8080 (any build before 1.2.4-8081).Affected if installed version falls within 1.2.x up to but not including 1.2.4-8081
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Verify QuickConnect is accessibleCheck if QuickConnect is enabled by navigating to Control Panel > QuickConnect in the SRM web interface, or inspect the configuration file at '/etc/synoinfo.conf' for 'quickconnect' settings via SSH.Affected if QuickConnect is enabled and accessible from external networks (the default remote access mechanism)
You are affected if your SRM version is between 1.2.0 and 1.2.3-8080 AND QuickConnect is enabled, since the vulnerability allows authentication bypass through inbound QuickConnect traffic.
Generated from the published advisory. Verify against your own configuration.
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 · scoped1.2.4-8081
Update Synology Router Manager to version 1.2.4-8081 or later to remediate the access control vulnerability. If immediate patching is not possible, disable QuickConnect functionality as a compensating control.
1.2.4-8081
- Access the Synology Router Manager (SRM) admin interface
- Navigate to Control Panel > System > Update & Restore
- Check for available updates or manually download SRM version 1.2.4-8081 from the official Synology download center (https://www.synology.com)
- Apply the SRM firmware update through the web interface
- After the router restarts, verify the update was successful by checking System Information > DSM version shows 1.2.4-8081 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2020-27655 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-27655 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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