CVE-2021-22885Network attack vector

Information disclosure via unintended route-helper execution

Published May 27, 2021 · Updated Aug 3, 2024

Information disclosure in vulnerable Rails Action Pack releases allows remote attackers to expose data through untrusted routing input. The polymorphic URL builder accepts strings in route arrays and converts them into route-helper method names, allowing attacker-controlled strings to invoke unintended helpers. Exposure requires an application to pass untrusted input to redirect_to or polymorphic_url; the published impact is limited to confidentiality.

CVSS severity7.5
High
EPSS probability4.16%
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

Information disclosure in vulnerable Rails Action Pack releases allows remote attackers to expose data through untrusted routing input. The polymorphic URL builder accepts strings in route arrays and converts them into route-helper method names, allowing attacker-controlled strings to invoke unintended helpers. Exposure requires an application to pass untrusted input to redirect_to or polymorphic_url; the published impact is limited to confidentiality.

The record

CVE
CVE-2021-22885
Published
May 27, 2021
Updated
Aug 3, 2024
Vendor
Rails
Product
Action Pack
Classifications
CWE-200, CWE-209, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=6.1.3.1, 6.0.3.7, 5.2.4.6, 5.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rails · Action Packversion=6.1.3.1, 6.0.3.7, 5.2.4.6, 5.2.6

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-209Generation of Error Message Containing Sensitive Information
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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