Vulnerability · Published Jul 31, 2020 · Assigned by GitHub_M
CVE-2020-15133Missing TLS certificate verification in Faye Websocket
High 8.0
In plain English
A high-severity improper certificate validation in faye-websocket from faye. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 60% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In faye-websocket before version 0.11.0, there is a lack of certification validation in TLS handshakes. The `Faye::WebSocket::Client` class uses the `EM::Connection#start_tls` method in EventMachine to implement the TLS handshake whenever a `wss:` URL is used for the connection. This method does not implement certificate verification by default, meaning that it does not check that the server presents a valid and trusted TLS certificate for the expected hostname. That means that any `wss:` connection made using this library is vulnerable to a man-in-the-middle attack, since it does not confirm the identity of the server it is connected to. For further background information on this issue, please see the referenced GitHub Advisory. Upgrading `faye-websocket` to v0.11.0 is recommended.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | ruby-faye-websocket | 0.11.0-1 | DEBIAN-CVE-2020-15133 |
| Debian:13 | ruby-faye-websocket | 0.11.0-1 | DEBIAN-CVE-2020-15133 |
| Debian:14 | ruby-faye-websocket | 0.11.0-1 | DEBIAN-CVE-2020-15133 |
| RubyGems | faye-websocket | 0.11.0 | GHSA-2v5c-755p-p4gv |
| Ubuntu:22.04:LTS | ruby-faye-websocket | no fix listed | UBUNTU-CVE-2020-15133 |
| Ubuntu:24.04:LTS | ruby-faye-websocket | no fix listed | UBUNTU-CVE-2020-15133 |
| Ubuntu:25.10 | ruby-faye-websocket | no fix listed | UBUNTU-CVE-2020-15133 |
| Ubuntu:26.04:LTS | ruby-faye-websocket | no fix listed | UBUNTU-CVE-2020-15133 |
| Ubuntu:26.10 | ruby-faye-websocket | no fix listed | UBUNTU-CVE-2020-15133 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| faye | faye-websocket | < 0.11.0 |
Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N