CVE-2020-35556
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 · uneditedAn issue was discovered in Acronis Cyber Protect before 15 Update 1 build 26172. Because the local notification service misconfigures CORS, information disclosure can occur.
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 · high confidenceA CORS (Cross-Origin Resource Sharing) misconfiguration in Acronis Cyber Protect's local notification service allows unauthorized cross-origin access to sensitive information. This vulnerability allows attackers to potentially retrieve confidential data through malicious web pages or scripts that exploit the improperly configured CORS policy.
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< 15= 15CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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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Verify Acronis Cyber Protect is installedLocate the Acronis Cyber Protect installation on the system - typical installation paths include C:\Program Files\Acronis\Cyber Protect or /opt/acronis/cyber-protect on Linux systems. Check for the presence of the core executable files or service components.Affected if Acronis Cyber Protect is not found on the system.
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Determine the installed versionOpen the Acronis Cyber Protect console or use the command line to retrieve the product version. In the console, navigate to Help > About. Alternatively, check the Windows Programs and Features list or the installed packages on Linux.Affected if The installed version is any version of 15.0.0 (builds prior to 26172) or any version below 15.0.0.
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Confirm the notification service is runningCheck if the Acronis Cyber Protect notification service is active. On Windows, open Services and look for 'Acronis Cyber Protect Notification Service' or similar. On Linux, check running processes for the notification service daemon.Affected if The notification service is running and exposed on a network port.
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Inspect the CORS configuration for the notification serviceExamine the configuration files associated with the notification service. Look for CORS-related settings in the notification service configuration, typically found in the same directory as the service or in a central config folder. Identify if the Access-Control-Allow-Origin header is set to a permissive value such as '*' or allows arbitrary domains.Affected if The CORS policy allows unrestricted or wildcard origins, or permits origins that are not explicitly trusted and authorized.
A system is affected if Acronis Cyber Protect version 15.0.0 (prior to build 26172) or any version below 15.0 is installed AND the notification service exposes a CORS policy that permits unauthorized cross-origin requests.
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.
From vendor data15
Update Acronis Cyber Protect to version 15 Update 1 build 26172 or later to receive the vendor patch. Alternatively, if patching is not immediately feasible, manually review and restrict the CORS configuration for the notification service to explicitly whitelist only trusted origins.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-35556 — 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-2020-35556 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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- 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