CVE-2010-1940 in Safari
Summary
by MITRE
Apple Safari 4.0.5 on Windows sends the "Authorization: Basic" header appropriate for one web site to a different web site named in a Location header received from the first site, which allows remote web servers to obtain sensitive information by logging HTTP requests. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 09/13/2021
This vulnerability in Apple Safari 4.0.5 on Windows represents a critical security flaw in the browser's handling of HTTP authentication credentials across domain boundaries. The issue stems from the browser's improper implementation of the HTTP authorization mechanism, where it fails to properly isolate authentication credentials when following redirects to different domains. When a user accesses a website that responds with a Location header directing the browser to another site, Safari incorrectly reuses the Authorization: Basic header from the original request, effectively transferring authentication credentials between unrelated domains.
The technical nature of this vulnerability aligns with CWE-200, which addresses information exposure, and CWE-352, which covers cross-site request forgery vulnerabilities. The flaw operates at the HTTP protocol level where the browser should enforce strict credential isolation policies but instead allows credential leakage between different web servers. This behavior creates a scenario where malicious servers can capture authentication tokens meant for one domain and potentially use them against other domains, particularly when those domains share similar authentication mechanisms or when users have previously authenticated to the first domain.
The operational impact of this vulnerability is significant as it enables attackers to perform credential harvesting attacks without requiring complex exploitation techniques. When a user visits a malicious website that immediately redirects to a legitimate service, the browser automatically includes the user's authentication credentials in the subsequent request. This allows unauthorized parties to access resources they should not be able to reach, potentially leading to data breaches, account takeovers, or unauthorized access to protected services. The vulnerability is particularly dangerous because it operates transparently to users who may not realize their credentials are being transferred between domains.
Mitigation strategies for this vulnerability require a multi-layered approach focusing on both browser updates and network-level protections. Organizations should immediately update Safari browsers to versions that address this credential leakage issue, as Apple would have released patches to fix the improper header handling. Network administrators should implement monitoring solutions to detect unusual patterns of credential transmission between domains, and organizations should consider implementing additional authentication controls such as token-based authentication or session management that reduces reliance on basic authentication headers. The ATT&CK framework categorizes this type of vulnerability under credential access techniques, specifically related to credential dumping and credential theft through network reconnaissance. Additionally, implementing proper HTTP security headers including Content Security Policy directives can help prevent unauthorized credential forwarding across domains, while regular security audits of web applications should include testing for cross-domain credential leakage scenarios.