CVE-2015-3658 in Safari
Summary
by MITRE
The Page Loading functionality in WebKit in Apple Safari before 6.2.7, 7.x before 7.1.7, and 8.x before 8.0.7, as used in Apple iOS before 8.4 and other products, does not properly consider redirects during decisions about sending an Origin header, which makes it easier for remote attackers to bypass CSRF protection mechanisms via a crafted web site.
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Analysis
by VulDB Data Team • 05/23/2022
The vulnerability identified as CVE-2015-3658 represents a critical flaw in WebKit's page loading implementation that affects Apple Safari and iOS browsers across multiple versions. This security weakness stems from improper handling of HTTP redirects during the decision-making process for Origin header transmission, creating a significant bypass opportunity for cross-site request forgery attacks. The flaw exists within the browser's core networking stack where redirect decisions influence security header behavior, fundamentally undermining the CSRF protection mechanisms that web applications rely upon for user safety.
The technical implementation of this vulnerability lies in how WebKit processes HTTP redirects and determines when to include Origin headers in subsequent requests. During the page loading sequence, when a browser encounters redirects from one domain to another, the system should carefully evaluate whether to transmit Origin headers based on the final destination. However, the flawed implementation fails to properly account for these redirect scenarios, leading to situations where Origin headers may be omitted or incorrectly handled during cross-origin requests. This behavior creates a window of opportunity for malicious actors to craft web pages that can bypass the same-origin policy protections that CSRF tokens typically enforce.
From an operational perspective, this vulnerability enables remote attackers to execute sophisticated cross-site request forgery attacks against users of affected browser versions. Attackers can construct malicious websites that manipulate the redirect chain to bypass CSRF protection mechanisms, potentially allowing unauthorized actions to be performed on behalf of authenticated users. The impact extends beyond simple data theft to include potential account takeovers, unauthorized transactions, and privilege escalation attacks. The vulnerability affects a broad range of Apple products including Safari browsers on desktop and mobile platforms, as well as iOS versions that rely on WebKit for rendering web content.
The security implications of CVE-2015-3658 align with CWE-346, which addresses "Origin Validation Error" in web applications, and maps to ATT&CK technique T1566.001 for "Phishing: Spearphishing Attachment" and T1566.002 for "Phishing: Spearphishing Link" where attackers can leverage this vulnerability to craft more effective phishing campaigns. The flaw essentially weakens the browser's security posture by creating a bypass mechanism that allows attackers to circumvent fundamental web security controls. Organizations using affected Apple products face significant risk exposure, particularly in environments where users interact with untrusted websites or where sensitive operations require robust CSRF protection. The vulnerability demonstrates how seemingly minor implementation details in browser security can have substantial consequences for overall web application security.
Mitigation strategies should focus on immediate browser updates to patched versions, as Apple released security updates for Safari 6.2.7, 7.1.7, and 8.0.7. Network administrators should implement additional security controls including content security policies, proper CSRF token implementation, and monitoring for suspicious redirect patterns. Organizations should also consider deploying web application firewalls and security scanning tools that can detect and block malicious redirect sequences. The vulnerability underscores the importance of maintaining up-to-date browser software and highlights the critical need for comprehensive security testing of browser components that handle cross-origin requests and security header generation.