Security readout for executives and security teams
Plain-English summary
This is a low-severity information disclosure issue in OTRS calendar access. A logged-in agent may be able to list calendar appointments without the permissions that should be required, exposing limited appointment information but not changing data or disrupting service.
Executive priority
Treat this as routine remediation unless calendars contain sensitive customer, incident, or staffing information. It should be included in normal OTRS patch cycles and access reviews, not handled as an emergency based on the provided evidence.
Technical view
CVE-2021-36091 is CWE-200 in OTRS calendar appointment authorization. The CVSS vector is AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N, indicating network reachability, low complexity, required low privileges and user interaction, with confidentiality impact only.
Likely exposure
Exposure is limited to organizations running affected OTRS versions: ((OTRS)) Community Edition 6.0.x from 6.0.1 onward, or OTRS 7.0.x before 7.0.27. Risk is higher where many agents have accounts or calendars contain sensitive operational information.
Exploitation context
The source bundle does not show CISA KEV listing or public active exploitation evidence. The issue requires an authenticated agent context and user interaction according to the CVSS vector, so this is not an unauthenticated remote takeover scenario.
Researcher notes
The core security failure is authorization enforcement around listing calendar appointments. Available evidence supports confidentiality impact only. The bundle does not provide exploit details, indicators of compromise, or a complete remediation statement for every affected Community Edition 6.0.x deployment.
Mitigation direction
- Identify all OTRS and ((OTRS)) Community Edition deployments and versions.
- Upgrade affected OTRS 7.0.x deployments to 7.0.27 or later.
- Apply Debian otrs2 security updates where OTRS is distro-managed.
- For Community Edition 6.0.x, check vendor or distributor guidance for supported remediation.
- Restrict agent accounts and calendar access to business-required users only.
Validation and detection
- Confirm production OTRS version is not in the affected version ranges.
- Review agent roles for unnecessary calendar-related permissions or broad group membership.
- Verify patched systems deny appointment listing to agents without required permissions.
- Check available audit logs for unexpected calendar appointment access.
- Confirm Debian-managed systems include the DLA 3551-1 otrs2 update where applicable.
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-36091 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-2021-14/CVE reference
- [debian-lts-announce] 20230831 [SECURITY] [DLA 3551-1] otrs2 security updateCVE reference · mailing-list
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.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.