CVE-2023-45289 in net-http-cookiejar
Summary
by MITRE • 03/06/2024
When following an HTTP redirect to a domain which is not a subdomain match or exact match of the initial domain, an http.Client does not forward sensitive headers such as "Authorization" or "Cookie". For example, a redirect from foo.com to www.foo.com will forward the Authorization header, but a redirect to bar.com will not. A maliciously crafted HTTP redirect could cause sensitive headers to be unexpectedly forwarded.
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Analysis
by VulDB Data Team • 04/15/2026
The vulnerability described in CVE-2023-45289 represents a critical security flaw in Go's http.Client implementation that affects how sensitive headers are handled during HTTP redirection processes. This issue stems from the client's strict domain matching logic that determines whether to forward authentication and session headers across redirects. The vulnerability specifically impacts applications that rely on Go's standard library for HTTP client operations, creating a potential vector for credential leakage and session hijacking attacks.
The technical flaw manifests in the http.Client's redirect handling mechanism where it only forwards sensitive headers such as Authorization and Cookie when the redirect target maintains a subdomain relationship with the original domain. This behavior follows a strict matching pattern where foo.com would properly forward headers to www.foo.com due to the subdomain relationship, but would not forward headers when redirecting to bar.com. The implementation does not account for the possibility that the redirect target might be a legitimate service that requires authentication credentials for proper operation, leading to unexpected behavior where legitimate requests lose their authentication context.
From an operational impact perspective, this vulnerability creates a significant risk for applications that utilize HTTP redirects as part of their normal operation. Attackers can exploit this behavior by crafting redirects that cause sensitive headers to be stripped from requests, potentially leading to authentication bypass scenarios or session manipulation. The vulnerability is particularly concerning because it can be leveraged to perform attacks against applications that depend on proper header forwarding for security functions, creating a situation where legitimate users may be unable to access protected resources due to header stripping, or attackers may gain unauthorized access by manipulating redirect chains to avoid header forwarding.
The security implications extend beyond simple credential leakage to encompass broader session management concerns and potential privilege escalation opportunities. This vulnerability aligns with CWE-284 (Improper Access Control) and CWE-306 (Missing Authentication) categories, as it can result in unauthorized access to protected resources due to improper handling of authentication tokens. The behavior can be exploited through various attack vectors including web cache poisoning, session hijacking, and credential harvesting attacks, particularly in environments where applications rely on HTTP redirects for navigation or service discovery. Organizations using Go applications that perform HTTP requests with redirects must consider this vulnerability as a potential threat to their security posture.
Mitigation strategies should focus on implementing proper header validation and handling mechanisms within applications, including explicit header management during redirect processing. Organizations should consider upgrading to patched versions of Go where available, implementing custom redirect handlers that maintain security headers when appropriate, and conducting thorough security reviews of applications that rely on HTTP redirect functionality. Additionally, monitoring for unexpected redirect patterns and implementing proper access controls can help detect and prevent exploitation of this vulnerability. The ATT&CK framework categorizes this issue under T1566 (Phishing) and T1071.004 (Application Layer Protocol: DNS) when used in conjunction with DNS-based redirect attacks, making it a significant concern for enterprise security teams.