Security readout for executives and security teams
Plain-English summary
This is a low-severity authorization flaw in an OTRS add-on. An authenticated agent could see and link customer Configuration Items even when General Catalog permissions should prevent it. The known impact is limited confidentiality exposure around asset or service records, not data modification or service disruption.
Executive priority
Handle in normal patch governance unless Config Items contain sensitive operational or customer data. Prioritize affected internet-accessible or large-agent deployments, but this does not warrant emergency response based on the provided evidence.
Technical view
CVE-2021-21436 affects OTRS AG OTRSCIsInCustomerFrontend 7.0.x through 7.0.14. The issue is improper permission enforcement for viewing and linking Config Items in the customer frontend. CVSS 3.1 is 3.5 with low privileges and user interaction required; confidentiality impact is low.
Likely exposure
Exposure is limited to organizations running OTRSCIsInCustomerFrontend 7.0.x version 7.0.14 or earlier. Risk is highest where many agents have accounts and Config Items contain sensitive customer, asset, or service relationship data.
Exploitation context
The source bundle does not show CISA KEV inclusion or active exploitation evidence. CVSS indicates network access, low attack complexity, low privileges, and required user interaction. Treat this as an access-control weakness requiring authenticated agent context, not an unauthenticated takeover issue.
Researcher notes
The evidence points to authorization bypass around General Catalog-based Config Item visibility and linking. Public details are sparse, so avoid assuming broader products, stronger impact, or exploit availability without vendor confirmation.
Mitigation direction
- Inventory OTRSCIsInCustomerFrontend deployments and versions.
- Review OTRS Security Advisory 2021-04 for vendor-fixed release guidance.
- Upgrade or remediate according to OTRS guidance where affected.
- Limit agent accounts to required roles and groups.
- Review General Catalog permissions for Config Item visibility.
Validation and detection
- Confirm whether OTRSCIsInCustomerFrontend is installed.
- Check whether version is 7.0.14 or earlier.
- Review agent roles against intended Config Item permissions.
- In non-production, verify restricted agents cannot view unauthorized Config Items.
- Review recent tickets for unexpected Config Item links.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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Open ATT&CK lookupCVE-2021-21436 mapping review
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Open ATT&CK lookup- Severity
- Low
- CVSS
- 3.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N2.11.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
3.5LowVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://otrs.com/release-notes/otrs-security-advisory-2021-04/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Permissions, Privileges, and Access Controls
Permissions, Privileges, and Access Controls represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.