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Nextcloud ServerApplication · Nextcloud

CVE-2017-0891

MEDIUM · 5.4 CVSS v3.0 Published 2017-05-08
Fix available
A fix is available. Upgrade to 9.0.58 / 10.0.5 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

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
Nextcloud Server before 9.0.58 and 10.0.5 and 11.0.3 are vulnerable to an inadequate escaping of error messages leading to XSS vulnerabilities in multiple components.

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 confidence

Nextcloud Server versions before 9.0.58, 10.0.5, and 11.0.3 contain Cross-Site Scripting (XSS) vulnerabilities caused by inadequate escaping of error messages across multiple components.

MitigationUpgrade Nextcloud Server to version 9.0.58, 10.0.5, or 11.0.3 or later to patch the XSS vulnerability in error message handling.

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
Nextcloud ServerApplication
Affected:< 9.0.58>= 10.0.0, < 10.0.5>= 11.0.0, < 11.0.3

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
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 checks

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

  1. Locate the installed Nextcloud version
    Check the version.php file in the Nextcloud root directory, or log into the Nextcloud admin interface and navigate to the administration settings to view the server version
    Affected if The version cannot be determined or is not visible in these standard locations
  2. Compare your version against the affected ranges
    Determine if your installed version falls into any of these ranges: below 9.0.58, between 10.0.0 and 10.0.4 inclusive, or between 11.0.0 and 11.0.2 inclusive
    Affected if Your installed version matches any of these ranges, indicating the missing security patches for CVE-2017-0891
  3. Verify the exact version number
    Confirm the full version number including patch level (for example, 10.0.4 or 11.0.2) from the version.php file or admin panel
    Affected if The version is 9.0.57 or lower, 10.0.0 through 10.0.4, or 11.0.0 through 11.0.2

You are affected if your Nextcloud Server version is 9.0.57 or lower, any version from 10.0.0 through 10.0.4, or any version from 11.0.0 through 11.0.2, as these versions contain the unpatched XSS vulnerability in error message handling.

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.

From vendor data
Upgrade available Upgrade to 9.0.58 / 10.0.5 / 11.0.3 or later
Fixed in 9.0.5810.0.511.0.3
Interim mitigation

Upgrade Nextcloud Server to version 9.0.58, 10.0.5, or 11.0.3 or later to patch the XSS vulnerability in error message handling.

Fix this in Nextcloud Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,512.

Scan for this in your stack

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dbcve dependency scanner

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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-2017-0891 in production — separate from our analysis above.

No notes yet

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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