Security readout for executives and security teams
Plain-English summary
Piranha CMS could store unsafe script content in a page title. A low-privileged user who can create pages could plant content that runs in another user’s browser when viewed. This is not a full server takeover in the supplied evidence, but it can affect confidentiality and integrity inside the CMS context.
Executive priority
Treat as a moderate-priority CMS hardening issue. Prioritize remediation for externally exposed sites, multi-user editorial environments, and instances where lower-privileged contributors can create content viewed by administrators or customers.
Technical view
CVE-2021-25977 is a stored cross-site scripting issue in PiranhaCMS versions 7.0.0 through 9.1.1. The page title field is improperly sanitized, allowing JavaScript execution after user interaction. CVSS 3.1 is 5.4 with low attack complexity, low privileges required, user interaction required, and changed scope.
Likely exposure
Exposure is likely limited to organizations running PiranhaCMS 7.0.0 through 9.1.1 where low-privileged users can create or edit pages. Public-facing CMS administration or multi-author publishing workflows increase practical risk.
Exploitation context
The source bundle does not show active exploitation, and KEV status is false. The vulnerability requires authenticated low-privileged access and a victim interaction path, so risk depends heavily on CMS roles, workflow, and who views created pages.
Researcher notes
The evidence supports stored XSS in the page title field, mapped to CWE-79. The bundle provides CVSS, affected range, and upstream commit reference, but does not provide exploit-in-the-wild evidence or a named fixed version. Avoid assuming broader PiranhaCMS components are affected.
Mitigation direction
- Identify all PiranhaCMS deployments and their versions.
- Review the linked upstream commit and vendor guidance for the fixed release.
- Upgrade affected instances according to vendor guidance.
- Limit page creation and editing to trusted users until remediated.
- Review existing page titles for suspicious script-like content.
Validation and detection
- Confirm whether PiranhaCMS versions fall within 7.0.0 through 9.1.1.
- Confirm which roles can create or edit page titles.
- Review CMS audit logs for unusual page title changes.
- Verify remediation against vendor guidance or the upstream commit.
- Confirm stored page titles are rendered safely after remediation.
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-2021-25977 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
- 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
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:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/PiranhaCMS/piranha.core/commit/543bc53c7dbd28c793ec960b57fb0e716c6b18d7CVE reference · x_refsource_MISC
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25977CVE reference · x_refsource_MISC
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.