GitHub Advisoryadvisory · Packagist
GHSA-4333-387x-w245 CI4MS: Blogs Tags Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS
CRITICAL
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- Aliases
- CVE-2026-34559
- Ecosystem
- Packagist
- Packages
- ci4-cms-erp/ci4ms
- Severity
- Critical
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L
- Weaknesses
- CWE-79
- Reviewed
- 2026-04-01
Affected packages
• Packagist ci4-cms-erp/ci4ms: < 0.31.0.0 → fixed in 0.31.0.0
Description
Summary
Vulnerability: Stored DOM XSS via Blog Tag Name (Persistent Payload Injection)
• Stored Cross-Site Scripting via Unsanitized Blog Tag Name in Blog Management
Description
The application fails to properly sanitize user-controlled input when creating or editing blog tags. An attacker can inject a malicious JavaScript payload into the tag name field, which is then stored server-side.
This stored payload is later rendered unsafely across public tag pages and administrative interfaces without proper output encoding, leading to stored cross-site scripting (XSS).
Affected Functionality
• Blog tag creation functionality
• Blog tag editing functionality
• Blog tag storage and retrieval logic
Attack Scenario
• An attacker creates or edits a blog tag name to include a malicious XSS payload.
• The application stores this value without sanitization or encoding.
• The payload persists and executes whenever the tag name is rendered in affected views.
Impact
• Persistent Stored XSS
• Execution of arbitrary JavaScript in victims’ browsers
• Privilege escalation when viewed by administrators or privileged users
• Full administrator account takeover
• Full account takeover across all roles
• Full compromise of the entire application
Endpoints:
• `/backend/blogs/tags/`
• `/blog/{id}`
Steps To Reproduce (POC)
1. Go to the Blog Tags management page
2. Create or edit a tag and insert an XSS payload into the tag name such as:
``
3. Save the tag
4. View a public blog page or the administrative interface where the tag is rendered
5. Notice the XSS payload executing automatically
Remediation
• Avoid unsafe DOM manipulation methods: Do not use `.html()`, `innerHTML`, or similar sink functions in client-side JavaScript or server-side templating (e.g., PHP). Even when user input flowing into these sinks is not immediately apparent, they can introduce Cross-Site Scripting (XSS) vulnerabilities that an attacker may exploit.
• Apply output encoding: Implement HTML entity encoding on all user-controlled data before rendering it in the browser. This helps neutralize potentially malicious input.
• Implement input sanitization: Ensure that all user-supplied input is properly sanitized before processing or output. Currently, no sanitization mechanisms are in place, which should be addressed as a priority.
• Enforce security headers and cookie attributes:
• Content Security Policy (CSP): Define and enforce a strict CSP to limit the execution of unauthorized scripts.
• HttpOnly flag: Set the `HttpOnly` attribute on session cookies to prevent client-side script access.
• SameSite attribute: Configure the `SameSite` cookie attribute to mitigate Cross-Site Request Forgery (CSRF) risks.
• Secure flag: Ensure all cookies are transmitted only over HTTPS by enabling the `Secure` attribute.
These measures collectively reduce the impact of XSS and help prevent escalation paths such as CSRF via XSS.
Ready Video POC:
https://mega.nz/file/GI9Bnbha#FkVY4K7AiuttnBGDFaCtxuJwKk-afRcKjYJnkqfLZOM
Related
Alias · CVE (1)
- CVE-2026-34559 CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme… vulnerability
Weakness · CWE (1)
- CWE-79 Improper Neutralization of Input During Web Page Generation weakness