Open Redirect in OAuth2 Proxy

MEDIUM 5.4CVE-2020-4037 · BIT-oauth2-proxy-2020-4037 · GHSA-5m6c-jp6f-2vcv · Published 29/06/2020 · updated 17/06/2026

Package	Affected versions	Patched versions
github.com/oauth2-proxy/oauth2-proxy Go	`≥ 5.1.1, < 6.0.0`	`6.0.0`
oauth2 proxy oauth2_proxy_project	`≥ 5.1.1, < 6.0.0`	`6.0.0`

Description

Impact

As users can provide a redirect address for the proxy to send the authenticated user to at the end of the authentication flow. This is expected to be the original URL that the user was trying to access. This redirect URL is checked within the proxy and validated before redirecting the user to prevent malicious actors providing redirects to potentially harmful sites.

NVD description

In OAuth2 Proxy from version 5.1.1 and less than version 6.0.0, users can provide a redirect address for the proxy to send the authenticated user to at the end of the authentication flow. This is expected to be the original URL that the user was trying to access. This redirect URL is checked within the proxy and validated before redirecting the user to prevent malicious actors providing redirects to potentially harmful sites. This has been fixed in version 6.0.0.

References

oauth2-proxy/oauth2-proxy security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2020-4037 · ADVISORY
oauth2-proxy/oauth2-proxy commit ee5662e · WEB
oauth2-proxy/oauth2-proxy release v6.0.0 · WEB

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