CVE-2020-8166

MEDIUM
4.3
CVSS Score
Published: July 2, 2020 at 06:35 PM UTC
Updated: June 17, 2026 at 03:25 AM UTC
2 products affected across 2 vendorsDebian LinuxRails

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Severity
MEDIUM4.3
Exploit prediction
EPSS 2%
SSVC
PoC

Description

A CSRF forgery vulnerability exists in rails < 5.2.5, rails < 6.0.4 that makes it possible for an attacker to, given a global CSRF token such as the one present in the authenticity_token meta tag, forge a per-form CSRF token.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.2.4.36.0.0 ≤ v < 6.0.3.1
Vendor states this is fixed in 5.2.4.3 (unaffected)
Affected range stops below 6.0.3.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_MISCMailing ListPatchThird Party Advisory
https://groups.google.com/g/rubyonrails-security/c/NOjKiGeXUgw
x_refsource_MISCExploitThird Party Advisory
https://hackerone.com/reports/732415
Vendor Advisoryx_refsource_DEBIANThird Party Advisory
https://www.debian.org/security/2020/dsa-4766

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-352

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