Summary
Open Redirect in st
st is a module for serving static files.
An attacker is able to craft a request that results in an HTTP 301 (redirect) to an entirely different domain.
A request for: http://some.server.com//nodesecurity.org/%2e%2e would result in a 301 to //nodesecurity.org/%2e%2e which most browsers treat as a proper redirect as // is translated into the current schema being used.
Mitigating factor:
In order for this to work, st must be serving from the root of a server (/) rather than the typical sub directory (/static/) and the redirect URL will end with some form of URL encoded .. ("%2e%2e", "%2e.", ".%2e").
Code example (provided by Xin Gao):
[example.js]
var st = require('st')
var http = require('http')
http.createServer(st(process.cwd())).listen(1337)
$ curl -v http://localhost:1337//cve.mitre.com/%2e%2e
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 1337 (#0)
> GET //cve.mitre.com/%2e%2e HTTP/1.1
> Host: localhost:1337
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< cache-control: public, max-age=600
< last-modified: Fri, 13 Oct 2017 22:56:33 GMT
< etag: "16777220-46488904-1507935393000"
< location: //cve.mitre.com/%2e%2e/
< Date: Fri, 13 Oct 2017 22:56:41 GMT
< Connection: keep-alive
< Content-Length: 30
<
* Connection #0 to host localhost left intact
Impact
Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.
CVE-2017-16224 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.2.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Update to version 1.2.2 or later.
Frequently Asked Questions
- What is CVE-2017-16224? CVE-2017-16224 is a medium-severity open redirect vulnerability in st (npm), affecting versions <= 1.2.1. It is fixed in 1.2.2. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
- How severe is CVE-2017-16224? CVE-2017-16224 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of st are affected by CVE-2017-16224? st (npm) versions <= 1.2.1 is affected.
- Is there a fix for CVE-2017-16224? Yes. CVE-2017-16224 is fixed in 1.2.2. Upgrade to this version or later.
- Is CVE-2017-16224 exploitable, and should I be worried? Whether CVE-2017-16224 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2017-16224 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2017-16224? Upgrade
stto 1.2.2 or later.