Security readout for executives and security teams
Plain-English summary
FactorJS Factor forum pages can reflect attacker-controlled tag or category URL values into the page. If a logged-in user opens a malicious link, JavaScript may run in their browser and expose session data. The sources identify this as medium severity and do not show known active exploitation.
Executive priority
Treat as a targeted web application risk, not an emergency. Prioritize internet-facing Factor forum deployments, especially where authenticated user sessions have business impact.
Technical view
CVE-2021-25983 is reflected XSS in the Factor forum plugin, affecting versions v1.3.8 through v1.8.30. The vulnerable inputs are the URL "tags" and "category" parameters. CVSS 3.1 is 6.1 with network access, low complexity, no privileges, required user interaction, and changed scope.
Likely exposure
Exposure is most likely where FactorJS Factor uses the forum plugin, runs versions v1.3.8 to v1.8.30, and publicly exposes tag or category browsing routes.
Exploitation context
The bundle says an unauthenticated attacker can run JavaScript and steal session cookies, but CVSS requires user interaction. No CISA KEV listing or cited source in the bundle supports active exploitation.
Researcher notes
Evidence is limited to the CVE description and referenced Factor source location. The bundle does not identify a fixed version, patch commit, or public exploit. Validation should focus on affected version, plugin presence, route exposure, and safe confirmation of reflected input handling.
Mitigation direction
- Inventory FactorJS Factor deployments and confirm forum plugin versions.
- Check FactorJS or maintainer guidance for fixed releases or official remediation.
- Upgrade or patch affected deployments if vendor guidance identifies a safe version.
- If no fix is available, consider disabling affected forum tag/category routes.
- Ensure session cookies use secure attributes where compatible with the application.
Validation and detection
- Confirm whether Factor versions fall between v1.3.8 and v1.8.30.
- Identify whether the forum plugin is enabled and externally reachable.
- Review tag and category rendering for untrusted URL data handling.
- Use only benign markers when testing reflection behavior.
- Check access logs for unusual tag or category URL values.
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-2021-25983 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
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/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:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/FactorJS/factor/blob/v1.8.30/%40plugins/plugin-forum/topic-list.vue#L141-L143CVE reference · x_refsource_MISC
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25983CVE 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.