Vulnerability advisory

GHSA-jp5v-5gx4-jmj9

Ability to forge per-form CSRF tokens in Rails

Published May 26, 2020Updated May 5, 2026OSV record ↗

Also known as CVE-2020-8166

Severity

CVSS 3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Affected versions

actionpack RubyGems

All actionpack advisories →

Affected	Fixed in
`5.0.0` to before 5.2.4.3	`5.2.4.3`Advisories →
Also listed as affected (55) `5.0.0` `5.0.0.1` `5.0.1` `5.0.1.rc1` `5.0.1.rc2` `5.0.2` `5.0.2.rc1` `5.0.3` `5.0.4` `5.0.4.rc1` `5.0.5` `5.0.5.rc1` `5.0.5.rc2` `5.0.6` `5.0.6.rc1` `5.0.7` `5.0.7.1` `5.0.7.2` `5.1.0` `5.1.0.beta1` `5.1.0.rc1` `5.1.0.rc2` `5.1.1` `5.1.2` `5.1.2.rc1` `5.1.3` `5.1.3.rc1` `5.1.3.rc2` `5.1.3.rc3` `5.1.4` `5.1.4.rc1` `5.1.5` `5.1.5.rc1` `5.1.6` `5.1.6.1` `5.1.6.2` `5.1.7` `5.1.7.rc1` `5.2.0` `5.2.0.beta1` `5.2.0.beta2` `5.2.0.rc1` `5.2.0.rc2` `5.2.1` `5.2.1.1` `5.2.1.rc1` `5.2.2` `5.2.2.1` `5.2.2.rc1` `5.2.3` `5.2.3.rc1` `5.2.4` `5.2.4.1` `5.2.4.2` `5.2.4.rc1`
`6.0.0` to before 6.0.3.1	`6.0.3.1`Advisories →
Also listed as affected (10) `6.0.0` `6.0.1` `6.0.1.rc1` `6.0.2` `6.0.2.1` `6.0.2.2` `6.0.2.rc1` `6.0.2.rc2` `6.0.3` `6.0.3.rc1`

Description

It is possible to, given a global CSRF token such as the one present in the authenticity_token meta tag, forge a per-form CSRF token for any action for that session.

Impact

Given the ability to extract the global CSRF token, an attacker would be able to construct a per-form CSRF token for that session.

Workarounds

This is a low-severity security issue. As such, no workaround is necessarily until such time as the application can be upgraded.