CVE-2021-21291
In OAuth2 Proxy before version 7.0.0, for users that use the whitelist domain feature, a domain that ended in a similar way to the intended domain could have been allowed as a redirect.
Does this matter?
Lower severity and a low EPSS score (1.58%). Track it; it rarely justifies an emergency change on its own.
Description
OAuth2 Proxy is an open-source reverse proxy and static file server that provides authentication using Providers (Google, GitHub, and others) to validate accounts by email, domain or group. In OAuth2 Proxy before version 7.0.0, for users that use the whitelist domain feature, a domain that ended in a similar way to the intended domain could have been allowed as a redirect. For example, if a whitelist domain was configured for ".example.com", the intention is that subdomains of example.com are allowed. Instead, "example.com" and "badexample.com" could also match. This is fixed in version 7.0.0 onwards. As a workaround, one can disable the whitelist domain feature and run separate OAuth2 Proxy instances for each subdomain.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.58% probability · 74th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- oauth2 proxy project/oauth2 proxy
- Source
- security-advisories@github.com
References
- https://github.com/oauth2-proxy/oauth2-proxy/commit/780ae4f3c99b579cb2ea9845121caebb6192f725Patch, Third Party Advisory
- https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.0.0Release Notes, Third Party Advisory
- https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-4mf2-f3wh-gvf2Exploit, Third Party Advisory
- https://pkg.go.dev/github.com/oauth2-proxy/oauth2-proxy/v7Product, Third Party Advisory
- https://github.com/oauth2-proxy/oauth2-proxy/commit/780ae4f3c99b579cb2ea9845121caebb6192f725Patch, Third Party Advisory
- https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.0.0Release Notes, Third Party Advisory
- https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-4mf2-f3wh-gvf2Exploit, Third Party Advisory
- https://pkg.go.dev/github.com/oauth2-proxy/oauth2-proxy/v7Product, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.