OtrsApplication

CVE-2021-36094

MEDIUM · 5.4 CVSS v3.1 Published 2021-09-06
Fix available
A fix is available. Upgrade to 7.0.29 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
It's possible to craft a request for appointment edit screen, which could lead to the XSS attack. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.28 and prior versions.

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

Cross-site scripting (XSS) vulnerability in OTRS Community Edition 6.0.x and OTRS 7.0.x allows attackers to inject malicious scripts through crafted requests to the appointment edit screen, potentially executing arbitrary JavaScript in other users' sessions.

MitigationApply vendor-supplied patch or upgrade to a patched version of OTRS (Community Edition 6.0.19+, OTRS 7.0.29+). Implement output encoding on the appointment edit screen as a compensating control.

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
OtrsApplication
Affected:>= 6.0.1>= 7.0.0, < 7.0.29

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:3.1/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. Determine installed OTRS version
    Access the OTRS admin panel and navigate to System Administration > System Information, or check the VERSION file in the OTRS installation directory.
    Affected if The installed version is 6.0.1 through 6.0.18, or 7.0.0 through 7.0.28.
  2. Identify OTRS edition
    Confirm whether the installation is OTRS Community Edition or OTRS (commercial). This is visible in the admin dashboard footer or System Information screen.
    Affected if Both OTRS Community Edition and OTRS versions within the affected ranges are vulnerable.
  3. Verify Calendar module is enabled
    Navigate to Admin > System Configuration > Framework > Frontend::Module and confirm whether the AgentCalendar or AgentAppointmentEdit module is registered and active.
    Affected if The appointment edit functionality is accessible to users.
  4. Check user access to appointment calendar
    Go to Admin > Role or User group configuration and verify which roles or users have permission to access the Calendar or Appointment feature.
    Affected if Any non-admin users have calendar/appointment access, making them potential targets.
  5. Inspect appointment edit screen for output encoding
    Create a test appointment and inject a benign script tag (such as <script>alert('test')</script>) into an appointment field, then save and view the appointment to see if the script executes.
    Affected if The injected script executes or renders unescaped in the browser, confirming the XSS vulnerability is present.

A user is affected if their OTRS version falls within 6.0.1-6.0.18 or 7.0.0-7.0.28 AND the appointment calendar module is enabled and accessible to users.

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 7.0.29 or later
Fixed in 7.0.29
Interim mitigation

Apply vendor-supplied patch or upgrade to a patched version of OTRS (Community Edition 6.0.19+, OTRS 7.0.29+). Implement output encoding on the appointment edit screen as a compensating control.

Recommended fix High confidence

OTRS 7.0.29 or later (or the latest 7.x stable release)

  1. 1. Back up your current OTRS database and configuration files.
  2. 2. Download OTRS 7.0.29 or later from the official OTRS download page (https://otrs.com/download/).
  3. 3. Stop the OTRS web server (e.g., Apache, Nginx).
  4. 4. Upgrade OTRS by running the system upgrade script following the official upgrade guide.
  5. 5. Clear all cache files by removing the var/tmp/* directory contents.
  6. 6. Restart the OTRS web server.
  7. 7. Verify the appointment edit screen functions correctly and the XSS vulnerability is resolved by testing with a crafted appointment request.
Caveat Review OTRS 7.0.x release notes for any breaking changes between your current version and 7.0.29, particularly regarding Perl module requirements and configuration changes.

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

Fix this in Otrs Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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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-2021-36094 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