Summary
Sails before 0.12.7 vulnerable to Broken CORS
Affected versions of sails have an issue with the CORS configuration where the value of the origin header is reflected as the value for the Access-Control-Allow-Origin header. This may allow an attacker to make AJAX requests to vulnerable hosts through cross-site scripting or a malicious HTML Document, effectively bypassing the Same Origin Policy.
Mitigating Factors
This is only an issue when allRoutes is set to true and origin is set to * or left commented out in the sails CORS config file.
The problem can be compounded when the cors credentials setting is not provided, because at that point authenticated cross domain requests are possible.
Impact
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 0.12.7 or later.
As this vulnerability is primarily a user error, the patch for the vulnerability will simply cause the application to write an error message to the console when a vulnerable configuration is used in a production environment.
Writing a proper CORS configuration is still the responsibility of the user, so it is necessary to check for the error message after installing the patch. Be sure you are not using allRoutes: true with origin:'*', and that you uncomment origin and set it to a reasonable value. Ensure that if origin is set to * that you truly mean for all other websites to be able to make cross-domain requests to your API.
Likewise, ensure credentials is uncommented out and set to the appropriate value. Make sure to explicitly set which origins may request resources via CORS.
Frequently Asked Questions
- What is CVE-2016-10549? CVE-2016-10549 is a high-severity security vulnerability in sails (npm), affecting versions < 0.12.7. It is fixed in 0.12.7.
- Which versions of sails are affected by CVE-2016-10549? sails (npm) versions < 0.12.7 is affected.
- Is there a fix for CVE-2016-10549? Yes. CVE-2016-10549 is fixed in 0.12.7. Upgrade to this version or later.
- Is CVE-2016-10549 exploitable, and should I be worried? Whether CVE-2016-10549 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-2016-10549 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-2016-10549? Upgrade
sailsto 0.12.7 or later.