CVE-2015-9256
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 · uneditedDatto ALTO and SIRIS devices allow remote attackers to obtain sensitive information via access to device/VM restore mount points, because they do not have ACLs by default.
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 confidenceDatto ALTO and SIRIS backup devices expose restore mount points that lack default Access Control Lists (ACLs), allowing remote unauthenticated attackers to access sensitive data stored in device or VM restore points.
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 dataall versionsall versionsall versionsall versionsall versionsall versionsall versionsall versionsCVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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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Identify the Datto device modelCheck the device model or firmware branding to confirm it is a Datto ALTO or SIRIS backup appliance. Look for model labels such as Alto 3, Alto 2, Alto XL, Siris 3, Siris 2, Siris 3 X All Flash, Siris Virtual, or Alto Imaged.Affected if The device is any of the listed Datto ALTO or SIRIS models.
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Verify restore mount point configurationAccess the device admin interface or command line and check whether restore mount points are enabled or exported. Look for restore, mount, or share configurations in the device management console.Affected if Restore mount points are enabled or exported on the device.
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Inspect ACL settings on restore mount pointsUse the operating system ACL tools (such as getfacl on Linux/Unix) or the device management interface to examine the Access Control List settings on the restore mount point directories. Check if default ACLs are defined or if permissions are set to allow unrestricted access.Affected if Restore mount points lack default ACLs or have overly permissive access controls allowing unauthenticated access.
If the device is a Datto ALTO or SIRIS model with restore mount points exposed and those mount points have no default ACLs configured, the environment is affected by CVE-2015-9256.
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 dataApply proper ACLs to all device and VM restore mount points on affected Datto ALTO and SIRIS devices to restrict unauthorized access and prevent information disclosure.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,304.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-9256 — 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-2015-9256 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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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.
- 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