Default development error handler in Ratpack is vulnerable to HTML content injection (XSS)
Versions of Ratpack from 0.9.10 through 1.7.5 are vulnerable to CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (aka. XSS) in the development error handler. An attacker can utilize this to perform XSS when an exception message contains untrusted data.
As a simplistic example:
RatpackServer startedServer = RatpackServer.start(server -> {
server.handlers(chain -> chain.all(ctx -> {
// User supplied query parameter
String message = ctx.getRequest().getQueryParams().get("message");
// User supplied data appended to the message in an exception
throw new RuntimeException("An error occurred: " + message);
}));
});Impact
- Cross-Site Scripting
Patches
This vulnerability has been patched in Ratpack version 1.7.6.
Workarounds
If you are unable to update your version of Ratpack, we recommend the following workarounds and mitigations.
- Ensure that development mode is disabled in production.
- Don't use real customer data (ie. untrusted user input) in development.
References
For more information
If you have any questions or comments about this advisory:
- Open an issue in ratpack/ratpack
- Ask in our Slack channel
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | io.ratpack:ratpack-core | < 1.7.6 | 1.7.6 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- Java / Kotlin (Maven)
- Package
io.ratpack:ratpack-core- Disclosed
- 27.01.2020
- Updated
- 11.10.2026 12:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-r2wf-q3x4-hrv9 - CC BY 4.0
Vulnerability history: io.ratpack:ratpack-core
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 4
- First → latest
- 10.2019 07.2021
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 2
- Medium 1
Disclosures per year
- 2019: 1
- 2020: 1
- 2021: 2
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 0
-
Default development error handler in Ratpack is vulnerable to HTML content injection (XSS) this entry
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