CVE-2020-28481
Insecure Defaults vulnerability in socket.io (npm)
What is CVE-2020-28481 About?
This vulnerability in socket.io before version 2.4.0 is due to insecure defaults related to CORS misconfiguration, where all domains are whitelisted. This flaw allows attackers to bypass Cross-Origin Resource Sharing restrictions, potentially leading to unauthorized data access or Cross-Site Request Forgery (CSRF) attacks. Exploiting this vulnerability is relatively easy given the default insecure configuration.
Affected Software
Technical Details
The socket.io package, in versions prior to 2.4.0, is configured by default to whitelist all domains for Cross-Origin Resource Sharing (CORS). This means that any web application from any origin can make requests to and receive responses from a vulnerable socket.io server without being blocked by CORS policies. The underlying mechanism involves a lack of strict origin validation in the server's CORS configuration, effectively setting Access-Control-Allow-Origin to * or a similar permissive setup by default. An attacker can leverage this by hosting malicious scripts on an arbitrary domain that can interact with the vulnerable socket.io endpoint, facilitating data exfiltration, session hijacking, or other client-side attacks.
What is the Impact of CVE-2020-28481?
Successful exploitation may allow attackers to bypass security restrictions, access sensitive information, perform unauthorized actions, or compromise user sessions.
What is the Exploitability of CVE-2020-28481?
Exploitation of this vulnerability is straightforward due to the insecure default configuration. It requires no authentication and can be performed remotely. Prerequisites involve identifying a server running a vulnerable version of socket.io with the default CORS settings. The risk of exploitation is increased when sensitive data is handled by the socket.io communication, as the unrestricted CORS policy makes it trivial for malicious origins to interact with the application.
What are the Known Public Exploits?
| PoC Author | Link | Commentary |
|---|---|---|
| No known exploits | ||
What are the Available Fixes for CVE-2020-28481?
Available Upgrade Options
- socket.io
- <2.4.0 → Upgrade to 2.4.0
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Book a demoAdditional Resources
- https://nvd.nist.gov/vuln/detail/CVE-2020-28481
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1056357
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSBOWER-1056358
- https://github.com/socketio/socket.io/issues/3671
- https://github.com/socketio/socket.io/commit/f78a575f66ab693c3ea96ea88429ddb1a44c86c7
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSBOWER-1056358
- https://github.com/socketio/socket.io/issues/3671
- https://snyk.io/vuln/SNYK-JS-SOCKETIO-1024859
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1056357
- https://osv.dev/vulnerability/GHSA-fxwf-4rqh-v8g3
What are Similar Vulnerabilities to CVE-2020-28481?
Similar Vulnerabilities: CVE-2017-1000378 , CVE-2018-1000136 , CVE-2019-10748 , CVE-2021-23395 , CVE-2022-24706
