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CVE Record

CVE-2021-25968: OpenCMS - Stored Cross-Site Scripting (XSS) in Sitemap

In “OpenCMS”, versions 10.5.0 to 11.0.2 are affected by a stored XSS vulnerability that allows low privileged application users to store malicious scripts in the Sitemap functionality. These scripts are executed in a victim’s browser when they open the page containing the vulnerable field.

MediumCVSS 5.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-25968 is a stored cross-site scripting issue in OpenCMS Sitemap functionality. A low-privileged application user could save script content that later runs in another user’s browser when they view the affected page. Business risk is mainly account/session exposure and unauthorized content actions.

Executive priority

Treat this as a moderate-priority web application fix. It is not described as actively exploited, but it can let a lower-privileged user affect administrators or editors through trusted CMS pages. Prioritize systems with broad contributor access.

Technical view

OpenCMS versions 10.5.0 through 11.0.2 are reported affected. The flaw is CWE-79 stored XSS in Sitemap fields, with CVSS 3.1 score 5.4. Exploitation requires low application privileges and victim interaction, can cross security scope, and affects confidentiality and integrity at low impact.

Likely exposure

Organizations running OpenCMS 10.5.0 to 11.0.2, especially where editors or other low-privileged users can modify Sitemap content, are the likely exposure group. Internet-facing administration or content workflows increase practical concern.

Exploitation context

The source bundle does not indicate known active exploitation, and KEV is false. The attack requires an authenticated low-privileged user and a victim opening affected content.

Researcher notes

Evidence identifies the vulnerable area and affected range, but the bundle does not name a specific patched OpenCMS release. The GitHub commit is relevant remediation evidence, but validation should stay aligned to official vendor guidance and local deployment configuration.

Mitigation direction

  • Inventory OpenCMS deployments and identify versions 10.5.0 through 11.0.2.
  • Check OpenCMS or Alkacon guidance for fixed versions or supported remediation.
  • Review the referenced commit for the vendor’s intended sanitization change.
  • Restrict Sitemap editing to trusted users until remediation is complete.
  • Review Sitemap content for unexpected script-like or active markup.

Validation and detection

  • Confirm whether each OpenCMS instance is within the affected version range.
  • Identify roles allowed to create or edit Sitemap content.
  • Verify Sitemap fields encode or sanitize user-controlled content before rendering.
  • Review content history for suspicious Sitemap edits by low-privileged users.
  • Confirm remediation against vendor guidance in a non-production environment.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · medium confidence lookup

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 lookup
cve · low confidence lookup

CVE-2021-25968 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
5.4CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N2.32.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.4Medium
CVSS 3.1 vector shape for CVE-2021-25968Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
org.opencmsopencms-core10.5.0, unspecifiedListed
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.