GHSA-GX4C-2HQX-CW2R

rclone: S3 backend does not strip X-Amz-Security-Token on a same-host HTTPS->HTTP redirect

func s3RedirectCrossesHost(req *http.Request, via []*http.Request) bool {
	if len(via) == 0 {
		return false
	}
	host := via[0].URL.Host
	for _, redirect := range via[1:] {
		if redirect.URL.Host != host {
			return true
		}
	}
	return host != req.URL.Host
}

func s3RedirectCrossesHost(req *http.Request, via []*http.Request) bool {
	if len(via) == 0 {
		return false
	}
	host := via[0].URL.Host
	for _, redirect := range via[1:] {
		if redirect.URL.Host != host {
			return true
		}
	}
	return host != req.URL.Host
}

=== RUN   TestSchemeDowngradeNotDetectedAsCrossHost
    redirect_scheme_test.go:23: initial=https://bucket.example.com final=http://bucket.example.com s3RedirectCrossesHost=false
--- PASS: TestSchemeDowngradeNotDetectedAsCrossHost (0.00s)

Disclosure of the AWS STS session token (X-Amz-Security-Token) in
cleartext for the remainder of its validity window. This is the exact class
of leak that e7b1eb774 was written to close, it just doesn't cover the
scheme-downgrade axis of "crossing a host".

GHSA-GX4C-2HQX-CW2R has a CVSS score of 3.1 (Low). The vector is reachable from an adjacent network, 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 (1.74.4); upgrading removes the vulnerable code path.

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Also compare URL.Scheme, so a scheme downgrade on the same host is treated
the same as a host change:

func s3RedirectCrossesHost(req *http.Request, via []*http.Request) bool {
	if len(via) == 0 {
		return false
	}
	scheme, host := via[0].URL.Scheme, via[0].URL.Host
	for _, redirect := range via[1:] {
		if redirect.URL.Host != host || redirect.URL.Scheme != scheme {
			return true
		}
	}
	return host != req.URL.Host || scheme != req.URL.Scheme
}

1. What is GHSA-GX4C-2HQX-CW2R? GHSA-GX4C-2HQX-CW2R is a low-severity security vulnerability in github.com/rclone/rclone (go), affecting versions <= 1.74.3. It is fixed in 1.74.4.
2. How severe is GHSA-GX4C-2HQX-CW2R? GHSA-GX4C-2HQX-CW2R has a CVSS score of 3.1 (Low). 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/rclone/rclone are affected by GHSA-GX4C-2HQX-CW2R? github.com/rclone/rclone (go) versions <= 1.74.3 is affected.
4. Is there a fix for GHSA-GX4C-2HQX-CW2R? Yes. GHSA-GX4C-2HQX-CW2R is fixed in 1.74.4. Upgrade to this version or later.
5. Is GHSA-GX4C-2HQX-CW2R exploitable, and should I be worried? Whether GHSA-GX4C-2HQX-CW2R 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-GX4C-2HQX-CW2R 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-GX4C-2HQX-CW2R? Upgrade github.com/rclone/rclone to 1.74.4 or later.

Other vulnerabilities in github.com/rclone/rclone