CVE-2020-26290 Critical security issues in XML encoding in Dex

Critical 9.3 Published 28 Dec 2020 Updated 4 Aug 2024

Attackers can bypass SAML signature validation in Dex due to XML encoding flaws, allowing unauthorized access if the SAML connector is enabled.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2020-26290?

CVE-2020-26290 is a critical vulnerability in dexidp dex, published on 28 Dec 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Dex is a federated OpenID Connect provider written in Go. In Dex before version 2.27.0 there is a critical set of vulnerabilities which impacts users leveraging the SAML connector. The vulnerabilities enables potential signature bypass due to issues with XML encoding in the underlying Go library. The vulnerabilities have been addressed in version 2.27.0 by using the xml-roundtrip-validator from Mattermost (see related references).

Weakness: CWE-347

Which versions are affected by CVE-2020-26290?

It affects 1 product.

Linux distribution packages (1)

dex-oidc openSUSE:Tumbleweed All versions 2.28.1-1.3

Products include Linuxfoundation Dex.

How do I fix CVE-2020-26290?

Upgrade to a fixed version.

Is CVE-2020-26290 being exploited?

There is no known exploitation of CVE-2020-26290 in the wild and no public exploit code.

Sources

Also known as openSUSE-SU-2024:10714-1.