CAPEC-198 — XSS Targeting Error Pages
CAPEC-198: XSS Targeting Error Pages
MITRE CAPEC attack pattern
| Status | Draft |
| Typical severity | Medium |
| Likelihood of attack | — |
| Catalogue | CAPEC 3.9 (2023-01-24) |
Description
An adversary distributes a link (or possibly some other query structure) with a request to a third party web server that is malformed and also contains a block of exploit code in order to have the exploit become live code in the resulting error page.
Where this sits in the chain
A finding maps to a weakness (CWE), a weakness is exploited by an attack pattern (CAPEC), and an attack pattern shows up in ATT&CK as observed adversary behaviour. This page is the middle hop.
Weaknesses exploited: CWE-81
Prerequisites
- A third party web server which fails to adequately sanitize messages sent in error pages.
- The victim must be made to execute a query crafted by the adversary which results in the infected error report.
Mitigations
- Design: Use libraries and templates that minimize unfiltered input.
- Implementation: Normalize, filter and use an allowlist for any input that will be used in error messages.
- Implementation: The victim should configure the browser to minimize active content from untrusted sources.