Security readout for executives and security teams
Plain-English summary
Wiki.js installations in the affected version range can let an editor upload a malicious SVG asset that runs script when another user views it. The reported impact is theft of JWT tokens and possible account takeover. This is not unauthenticated, but it matters where editors are numerous or content review is weak.
Executive priority
Treat as a near-term remediation item for affected Wiki.js deployments. It is not rated critical, but account takeover through a trusted collaboration platform can create meaningful follow-on risk, especially for internal documentation, credentials, or operational runbooks.
Technical view
CVE-2021-25993 is a stored XSS issue in Requarks Wiki.js versions 2.0.0-beta.147 through 2.5.255. The flaw is tied to SVG asset uploads in pages by low-privileged editor users. CVSS 3.1 is 5.4 with PR:L, UI:R, scope changed, and low confidentiality and integrity impact.
Likely exposure
Exposure is most likely in self-hosted Wiki.js instances within the affected version range where editor users can upload page assets, especially SVG files. Anonymous internet exposure is not required, but externally accessible wikis increase business risk if compromised editor accounts exist.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires editor-level privileges and a victim viewing the stored content. The reported outcome is token theft leading to possible account takeover.
Researcher notes
Evidence supports stored XSS via uploaded SVG assets, not remote unauthenticated exploitation. The source bundle names affected versions and a fixing commit reference but does not provide a detailed vendor advisory or separate mitigation procedure. Avoid claiming active exploitation without new evidence.
Mitigation direction
- Identify all Wiki.js instances and confirm whether versions are 2.0.0-beta.147 through 2.5.255.
- Follow Requarks guidance and update to a release outside the affected range.
- Temporarily restrict editor and asset-upload permissions until the instance is remediated.
- Consider blocking or tightly reviewing SVG uploads where operationally feasible.
- Rotate JWT/session secrets or user sessions if suspicious uploaded assets are found.
Validation and detection
- Inventory Wiki.js versions across production, staging, and internal knowledge-base systems.
- Review which users or groups have editor and asset-upload permissions.
- Check uploaded assets for unexpected SVG files from editor accounts.
- Confirm the installed build includes the referenced Requarks fix commit or a later vendor release.
- Review access logs for views of suspicious uploaded SVG assets.
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-2021-25993 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/Requarks/wiki/commit/5d3e81496fba1f0fbd64eeb855f30f69a9040718CVE reference · x_refsource_MISC
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25993CVE 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.