CVE-2020-8166
MEDIUM4.3EPSS 0.44%Ability to forge per-form CSRF tokens in Rails
Published: 5/26/2020Modified: 5/5/2026
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.
Affected packages (2)
- Debian/railsfrom 0, < 2:5.2.4.3+dfsg-1
- RubyGems/actionpack>= 5.0.0, < 5.2.4.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N |
References (8)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2020-8166
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2020-8166
- PATCHhttps://github.com/rails/rails
- WEBhttps://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2020-8166.yml
- WEBhttps://groups.google.com/forum/#!topic/rubyonrails-security/NOjKiGeXUgw
- WEBhttps://groups.google.com/g/rubyonrails-security/c/NOjKiGeXUgw
- WEBhttps://hackerone.com/reports/732415
- WEBhttps://www.debian.org/security/2020/dsa-4766