CVE-2020-27847: Authentication Bypass in dex
Summary
CVE-2020-27847: Authentication Bypass in dex. Affects github.com/dexidp/dex versions < 2.27.0. Fixed in 2.27.0. How to fix ↓
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Background
The github.com/dexidp/dex library is a popular Go package used for processing SAML authentication. It provides functionality for SAML Signature Validation. Dex versions before 2.27.0 are affected by a vulnerability in the SAML connector, which allows an attacker to bypass SAML authentication. This vulnerability poses a critical threat to the confidentiality, integrity, and availability of systems utilizing dex.
Vulnerability Detail
The vulnerability in the SAML connector of dex arises from a flaw in the SAML Signature Validation process. By exploiting this flaw, an attacker can bypass SAML authentication, gaining unauthorized access to the system. This can lead to unauthorized disclosure of sensitive information, modification of data, and disruption of system availability. The vulnerability has a CVSS score of 9.8, indicating its severity.
How To Fix
Latest published version: v2.13.0+incompatible as of 23 Oct 2026
go get github.com/dexidp/dex@v2.13.0+incompatibleUpgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
2.27.0
This is the first release that contains the fix.
go get github.com/dexidp/dex@v2.27.0Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There is no known workaround for this vulnerability. It is crucial to apply the fix by upgrading to dex version 2.27.0 or later.
Conclusion
The vulnerability in the SAML connector of dex allows for authentication bypass, posing a significant risk to the confidentiality, integrity, and availability of affected systems. It is crucial to upgrade to dex version 2.27.0 or later to mitigate this vulnerability. For further support on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for github.com/dexidp/dex →
FAQ
The vulnerability allows an attacker to bypass SAML authentication, potentially leading to unauthorized access, data disclosure, and system disruption.
Versions of dex before 2.27.0 are affected by this vulnerability.
Yes, the fix for this vulnerability is available in dex version 2.27.0 and later. It is recommended to upgrade to the fixed version.
No, there are no known workarounds for this vulnerability. Upgrading to the fixed version is the only solution.
The CVSS score of this vulnerability is 9.8, indicating its critical severity.
Related vulnerabilities
Recent vulnerabilities recorded for github.com/dexidp/dex.
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