Security readout for executives and security teams
Plain-English summary
A remote sender can trigger cross-site scripting when a crafted email appears in affected OTRS ticket overview screens. The main business risk is unauthorized disclosure of information visible to the web session processing or viewing the overview. The source bundle does not cite active exploitation.
Executive priority
Prioritize remediation for internet-facing or email-connected OTRS systems. The issue can be reached through normal email intake and threatens confidentiality, but the provided sources do not show active exploitation or integrity impact.
Technical view
CVE-2021-21441 is a CWE-79 XSS issue in OTRS ticket overview rendering. The described attack requires only sending specially crafted email to the system; no authentication or user interaction is required. CVSS 3.1 is 7.5, with high confidentiality impact and no stated integrity or availability impact.
Likely exposure
Organizations using affected OTRS Community Edition 6.0.x from 6.0.1 onward, or OTRS 7.0.x through 7.0.26, are potentially exposed, especially where inbound email is processed into tickets and ticket overview screens are used.
Exploitation context
The bundle marks CISA KEV as false and provides no cited evidence of active exploitation. The vulnerability is still operationally serious because the attack path is remote, unauthenticated, low complexity, and tied to normal email intake.
Researcher notes
The source bundle does not include exploit details or exact fixed upstream versions. Treat this as an email-triggered XSS exposure in overview rendering and validate by version, advisory status, and distribution package updates rather than speculative product assumptions.
Mitigation direction
- Review OTRS Security Advisory 2021-11 and apply the vendor-recommended update.
- For Debian LTS otrs2 deployments, apply the DLA 3551-1 security update.
- Restrict access to OTRS staff interfaces where possible.
- Monitor vendor and distribution advisories for exact fixed package guidance.
Validation and detection
- Inventory OTRS and otrs2 versions in production and staging.
- Confirm whether inbound email automatically creates or updates tickets.
- Check whether affected ticket overview screens are reachable by staff accounts.
- Verify that vendor or Debian security updates are installed.
- Review web logs and ticket mail around suspicious crafted messages.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2021-21441 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:N/UI:N/S:U/C:H/I:N/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://otrs.com/release-notes/otrs-security-advisory-2021-11/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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.