CVE-2020-11020Public exploitNetwork attack vector

Authentication bypass via prefix-matched meta channels

Published Apr 29, 2020 · Updated Aug 4, 2024

Improper authentication in affected Faye Node.js and Ruby servers allows remote attackers to subscribe to protected channels. The server parses a namespaced value such as /meta/subscribe/x as an exact meta operation while extensions commonly compare only /meta/subscribe. A network-reachable server must use an affected release and a server-side access-control extension with an exact channel check; successful exploitation grants an unauthenticated client access to otherwise restricted messages.

CVSS severity8.5
High
EPSS probability1.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper authentication in affected Faye Node.js and Ruby servers allows remote attackers to subscribe to protected channels. The server parses a namespaced value such as /meta/subscribe/x as an exact meta operation while extensions commonly compare only /meta/subscribe. A network-reachable server must use an affected release and a server-side access-control extension with an exact channel check; successful exploitation grants an unauthenticated client access to otherwise restricted messages.

The record

CVE
CVE-2020-11020
Published
Apr 29, 2020
Updated
Aug 4, 2024
Vendor
Faye
Product
Faye
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.5.0, < 1.0.4
  2. Affected versionversion=>= 1.1.0, < 1.1.3
  3. Affected versionversion=>= 1.2.0, < 1.2.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Faye · Fayeversion=>= 0.5.0, < 1.0.4; version=>= 1.1.0, < 1.1.3; version=>= 1.2.0, < 1.2.5

Published CVSS scores

8.5GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo