CVE-2015-0818 in Firefox
Summary
by MITRE
Mozilla Firefox before 36.0.4, Firefox ESR 31.x before 31.5.3, and SeaMonkey before 2.33.1 allow remote attackers to bypass the Same Origin Policy and execute arbitrary JavaScript code with chrome privileges via vectors involving SVG hash navigation.
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Analysis
by VulDB Data Team • 10/22/2024
The vulnerability described in CVE-2015-0818 represents a critical security flaw in Mozilla Firefox and SeaMonkey browsers that enables remote code execution with elevated privileges. This issue affects versions prior to Firefox 36.0.4, Firefox ESR 31.x before 31.5.3, and SeaMonkey before 2.33.1, making it a widespread concern across multiple browser versions. The vulnerability specifically exploits the Same Origin Policy bypass mechanism through SVG hash navigation, allowing attackers to execute arbitrary JavaScript code with chrome privileges, which represents a significant escalation from regular user privileges to system-level access.
The technical flaw involves the improper handling of SVG (Scalable Vector Graphics) elements when navigating to hash fragments within documents. When browsers process SVG content containing hash references, the implementation fails to properly enforce cross-origin restrictions that should prevent scripts from accessing resources from different origins. This weakness occurs during the processing of SVG elements that reference external resources through hash navigation, enabling attackers to craft malicious SVG content that can bypass security boundaries. The vulnerability leverages the fact that certain SVG elements can trigger privileged operations when navigating to specific hash values, allowing attackers to execute code within the browser's privileged context. This behavior directly violates the fundamental security principle of same-origin policy enforcement, which is designed to prevent unauthorized access between different security domains.
The operational impact of this vulnerability is severe and multifaceted. Attackers can exploit this flaw to perform cross-site scripting attacks that operate with chrome privileges, effectively giving them access to the browser's most privileged execution environment. This elevated privilege level allows malicious actors to access sensitive data, manipulate browser functionality, and potentially escalate their attack to compromise the underlying operating system. The vulnerability enables attackers to bypass typical security measures that protect against malicious scripts, making it particularly dangerous in environments where users browse untrusted websites. The attack vector involving SVG hash navigation is particularly insidious because SVG content can be embedded in web pages, making exploitation occur through normal browsing activities without requiring user interaction beyond visiting a malicious site.
The security implications extend beyond simple privilege escalation to encompass broader system compromise potential. This vulnerability aligns with CWE-284 (Improper Access Control) and represents a classic example of how improper enforcement of security boundaries can lead to privilege escalation. From an attack framework perspective, this vulnerability maps to techniques described in the MITRE ATT&CK framework under privilege escalation and defense evasion tactics. The flaw demonstrates how web browser security mechanisms can be circumvented through careful manipulation of document parsing and navigation behaviors. Organizations using affected browser versions face significant risk of data breaches, system compromise, and potential lateral movement within networks. The vulnerability particularly affects enterprise environments where users may encounter malicious content through various attack vectors including phishing emails, compromised websites, or social engineering campaigns.
Mitigation strategies for this vulnerability require immediate patching of affected browser versions to the latest secure releases. Organizations should implement comprehensive browser update policies and ensure all users maintain current versions of their browsers. Additional protective measures include implementing content security policies that restrict SVG content loading, using web application firewalls to monitor for suspicious SVG content, and deploying browser hardening configurations that limit the execution of privileged operations. Security teams should also consider implementing user education programs to recognize potentially malicious SVG content and monitor network traffic for exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify systems running outdated browser versions. The remediation process must also include monitoring for exploitation attempts and ensuring that browser security features such as sandboxing and privilege separation remain active and properly configured.