GHSA-RF68-8GJR-36Q7

Nezha: OAuth2 redirecturi Host header injection regression when dashboardhost is empty

GET /api/v1/oauth2/github?type=1 HTTP/1.1
Host: evil.attacker.test
X-Forwarded-Proto: https

redirect_uri=https%3A%2F%2Fevil.attacker.test%2Fapi%2Fv1%2Foauth2%2Fcallback

func TestOAuth2Redirect_RegressionWhenDashboardHostEmptyReflectsForgedHost(t *testing.T) {
    defer setupOAuth2Test(t)()
    singleton.Conf.InstallHost = "legit-dashboard.example.com"
    singleton.Conf.DashboardHost = ""
    singleton.Conf.Oauth2["github"] = &model.Oauth2Config{
        ClientID: "client-id",
        ClientSecret: "client-secret",
        Endpoint: model.Oauth2Endpoint{AuthURL: "https://idp.example.test/authorize", TokenURL: "https://idp.example.test/token"},
        Scopes: []string{"openid"},
    }

    c, _ := newOAuth2Ctx(t)
    c.Params = gin.Params{{Key: "provider", Value: "github"}}
    c.Request.Host = "evil.attacker.test"
    c.Request.URL.RawQuery = "type=1"
    c.Request.Header.Set("X-Forwarded-Proto", "https")

    resp, err := oauth2redirect(c)
    require.NoError(t, err)

    parsed, err := url.Parse(resp.Redirect)
    require.NoError(t, err)
    require.Equal(t, "https://evil.attacker.test/api/v1/oauth2/callback", parsed.Query().Get("redirect_uri"))
}

host := c.Request.Host
if !singleton.IsReservedDashboardHost(host) && singleton.Conf != nil && singleton.Conf.DashboardHost != "" {
    host = singleton.Conf.DashboardHost
}
return scheme + host + "/api/v1/oauth2/callback"

An attacker who can get a victim to start OAuth2 login through a request that reaches Nezha with a forged Host header can make Nezha send an attacker-controlled callback URL as the OAuth2 redirect_uri. If the configured OAuth2 provider accepts that redirect URI, the victim's authorization code is sent to the attacker origin. The attacker can then complete the OAuth2 binding or login flow described in GHSA-9rc6.

This is configuration-dependent, but it affects a realistic upgrade/default state because dashboard_host is a new optional field. The original v2.2.0 fix fell back to install_host; current v2.2.3 only falls back when dashboard_host is non-empty.

Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.

Kodem intelligence

Already deployed Kodem?

Build the OAuth2 callback URL from a deterministic configured origin. For example:

1. Use DashboardHost when it is set.
2. Otherwise fall back to InstallHost if it is set, preserving the v2.2.0 invariant for existing deployments.
3. If neither value is set, reject OAuth2 redirect initiation with a configuration error instead of reflecting request Host.

Please also add a regression test that InstallHost plus empty DashboardHost does not reflect a forged Host into redirect_uri.

1. What is GHSA-RF68-8GJR-36Q7? GHSA-RF68-8GJR-36Q7 is a low-severity open redirect vulnerability in github.com/nezhahq/nezha (go), affecting versions = 2.2.3. No fixed version is listed yet. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
2. Which versions of github.com/nezhahq/nezha are affected by GHSA-RF68-8GJR-36Q7? github.com/nezhahq/nezha (go) versions = 2.2.3 is affected.
3. Is there a fix for GHSA-RF68-8GJR-36Q7? No fixed version is listed for GHSA-RF68-8GJR-36Q7 yet. Monitor the advisory for updates and apply mitigations in the interim.
4. Is GHSA-RF68-8GJR-36Q7 exploitable, and should I be worried? Whether GHSA-RF68-8GJR-36Q7 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether GHSA-RF68-8GJR-36Q7 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix GHSA-RF68-8GJR-36Q7? No fixed version is listed yet. In the interim: Validate redirect destinations against an allowlist of permitted URLs or paths. Reject destinations that include an unexpected authority component.