# CVE-2019-10775: ecstatic denial of service via URL parameter parsing

Source: https://junglewise.ai/threats/cve-2019-10775-ecstatic-denial-of-service-via-url-parameter-parsing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2020-12-15. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2019-10775 · Severity: info · CVSS 7.5 · Published 2020-12-15

ecstatic is a lightweight static file server middleware used to serve files in Node.js applications. A denial of service vulnerability in its URL parameter parsing could allow an attacker to crash applications using this library by sending a specially crafted request with invalid header characters, causing the server to become unavailable.

Technologies: [ecstatic (npm)](https://junglewise.ai/threats/technologies/ecstatic). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2019-10775 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2019-10775 being exploited in the wild.

**How severe is CVE-2019-10775?** Informational severity, with a CVSS score of 7.5, published 15 December 2020.

**Which products and versions are affected?** ecstatic (npm) SEMVER:introduced=0,fixed=4.1.3.

**Is there a fix for CVE-2019-10775?** Yes. ecstatic (npm): upgrade to 4.1.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2019-10775 attacked?** It is attacked over the network.

**Am I affected by CVE-2019-10775?** Check whether you run ecstatic (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- ecstatic (npm): upgrade to 4.1.3 or later

  ```sh
  npm install ecstatic@4.1.3
  ```


## Technical details

The vulnerability exists in ecstatic's URL parameter parsing during redirect handling. When processing requests with certain URL parameters (specifically containing invalid characters like \x0c), the library attempts to redirect the URL but fails to properly sanitize the input, resulting in a TypeError when invalid header characters are included in the response. The vulnerability is triggered via a network request and requires no authentication. An attacker can exploit this by sending a crafted URL (e.g., with a form-feed character in the query string) to crash the application. The issue is tracked as CWE-400 (uncontrolled resource consumption). Patched versions 4.1.3 and later address this vulnerability.

## Affected products

- ecstatic ecstatic <4.1.3

## Identifiers

- CVE-2019-10775
- GHSA-jc84-3g44-wf2q

## Timeline

- 2019-12-31: disclosed
- 2020-12-15: advisory: GHSA advisory published

## References

- [https://snyk.io/vuln/SNYK-JS-ECSTATIC-540354](https://snyk.io/vuln/SNYK-JS-ECSTATIC-540354)

## Related threats

- [ecstatic open redirect vulnerability](https://junglewise.ai/threats/ecstatic-open-redirect-vulnerability-4eae3a4a)
- [ecstatic open redirect vulnerability](https://junglewise.ai/threats/ecstatic-open-redirect-vulnerability-498cb2d3)
- [ecstatic denial of service via HTTP headers](https://junglewise.ai/threats/cve-2015-9242-ecstatic-denial-of-service-via-http-headers)
- [ecstatic denial of service via null byte payload](https://junglewise.ai/threats/cve-2016-10703-ecstatic-denial-of-service-via-null-byte-payload)