ruby-faye-websocket — security advisory
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.
- Products
- ruby-faye-websocket
- Affected versions
- 0.10.7-1, 0.11.0-1, 0.12.0-1
- Fixed versions
- Not specified
- CVEs
- CVE-2020-15133
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 00:51 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2020-15133
ruby-faye-websocket
Fixed versions: Not specified
ruby-faye-websocket
Fixed versions: Not specified
ruby-faye-websocket
Fixed versions: Not specified
ruby-faye-websocket
Fixed versions: Not specified
ruby-faye-websocket
Fixed versions: Not specified
ruby-faye-websocket
Fixed versions: Not specified
Complete source record
{
"id": "369cfbd49d62648e55ac4793fff850f6006f5db7ac11d096fda7f4f970ecfc47",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2020-15133",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2020-15133",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2020-15133",
"products": [
{
"name": {
"value": "ruby-faye-websocket",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.10.7-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "ruby-faye-websocket",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.11.0-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "ruby-faye-websocket",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.11.0-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "ruby-faye-websocket",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.11.0-1",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "ruby-faye-websocket",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.11.0-1",
"evidence": "/affected/4/versions"
},
{
"value": "0.12.0-1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "ruby-faye-websocket",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.11.0-1",
"evidence": "/affected/5/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2020-15133",
"aliases": [
"UBUNTU-CVE-2020-15133"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-faye-websocket",
"purl": "pkg:deb/ubuntu/ruby-faye-websocket?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"0.10.7-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-15133.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ruby-faye-websocket",
"binary_version": "0.10.7-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-faye-websocket",
"purl": "pkg:deb/ubuntu/ruby-faye-websocket?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"0.11.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-15133.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ruby-faye-websocket",
"binary_version": "0.11.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-faye-websocket",
"purl": "pkg:deb/ubuntu/ruby-faye-websocket?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"0.11.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-15133.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ruby-faye-websocket",
"binary_version": "0.11.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-faye-websocket",
"purl": "pkg:deb/ubuntu/ruby-faye-websocket?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"0.11.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-15133.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ruby-faye-websocket",
"binary_version": "0.11.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-faye-websocket",
"purl": "pkg:deb/ubuntu/ruby-faye-websocket?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"0.11.0-1",
"0.12.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-15133.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ruby-faye-websocket",
"binary_version": "0.12.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-faye-websocket",
"purl": "pkg:deb/ubuntu/ruby-faye-websocket?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"0.11.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-15133.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ruby-faye-websocket",
"binary_version": "0.11.0-1"
}
]
}
}
],
"modified": "2026-10-17T12:56:11.492309983Z",
"provider": "osv",
"upstream": [
"CVE-2020-15133"
],
"references": [
"https://ubuntu.com/security/CVE-2020-15133",
"https://github.com/faye/faye-websocket-ruby/security/advisories/GHSA-2v5c-755p-p4gv",
"https://github.com/faye/faye-websocket-ruby/pull/129",
"https://blog.jcoglan.com/2020/07/31/missing-tls-verification-in-faye/",
"https://www.cve.org/CVERecord?id=CVE-2020-15133"
]
},
"related_cves": [
{
"value": "CVE-2020-15133",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 354932,
"published_at": "2020-07-31T18:15:00+00:00"
}