CVE intelligence and bounded remediation
CVE-2021-21260 — Bigprof Online Invoicing System security vulnerability
Online Invoicing System (OIS) is open source software which is a lean invoicing system for small businesses, consultants and freelancers created using AppGini. In OIS version 4.0 there is a stored XSS which can enables an attacker takeover of the admin account through a payload that extracts a csrf token and sends a request to change password. It has been found that Item description is reflected without sanitization in app/items_view.php which enables the malicious scenario.
- Severity
- High
- CVSS
- 7.6 (3.1)
- Published
- 2021-01-22
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-79
Affected products
- bigprof / online_invoicing_system / 4.0
Matched remediation archetype
Cross-site scripting and unsafe browser output
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
- Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
- Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.
Remediate safely
- Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
- Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
- Update affected rendering components and add tests for every output context using inert sentinel markup.
Authoritative sources
Complete CVE record and remediation plan
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