Open Redirect in Oauth2 Proxy
CVE-2020-11053
In OAuth2 Proxy before 5.1.1, there is an open redirect vulnerability. 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. However, by crafting a redirect URL with HTML encoded whitespace characters the validation could be bypassed and allow a redirect to any URL provided. This has been patched in 5.1.1.
Vulnerability class: Open Redirect
EPSS: 0.008 (53.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L.
Affected products
- Oauth2 Proxy — versions < 5.1.1
- Oauth2_proxy_project Oauth2_proxy
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2020-11053?
- CVE-2020-11053 is a high-severity vulnerability in Oauth2 Proxy, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 7.1/10. Published 2020-05-07.
- How severe is CVE-2020-11053?
- High severity. CVSS v3 base score is 7.1 out of 10.