URL Redirection to Untrusted Site ('Open Redirect')
Sourcegraph before 3.15.1 has a vulnerable authentication workflow because of improper validation in the SafeRedirectURL method in cmd/frontend/auth/redirect.go, such as for the //foo//example.com substring.
CWE-601 - Open Redirect
An open redirect attack employs a URL parameter, HTML refresh tags, or a DOM based location change to exploit the trust of a vulnerable domain to direct the users to a malicious website. The attack could lead to higher severity vulnerabilities such as unauthorized access control, account takeover, XSS, and more.