CVE-2019-5144 in Safari
Summary
by MITRE
A freed memory access vulnerability exists in the SVG Marker Element feature of Apple Safari's WebKit version 13.0.2. A specially crafted HTML web page can cause a use after free, resulting in memory corruption and possibly arbitrary code execution. To trigger this vulnerability, a specifically crafted HTML web page needs to be opened in the browser.
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Analysis
by VulDB Data Team • 03/11/2024
The vulnerability identified as CVE-2019-5144 represents a critical use after free condition within Apple Safari's WebKit rendering engine, specifically affecting version 13.0.2. This flaw manifests in the SVG Marker Element processing functionality, where improper memory management allows attackers to manipulate freed memory locations. The vulnerability stems from insufficient validation mechanisms during the handling of Scalable Vector Graphics elements, particularly when marker elements are processed in conjunction with other SVG components. The issue is classified under CWE-416 which specifically addresses use after free vulnerabilities, where memory that has been freed is accessed again, potentially leading to unpredictable behavior and security breaches.
The technical exploitation of this vulnerability requires careful crafting of HTML content that triggers the specific code path involving SVG marker elements within WebKit's rendering pipeline. When a user opens a maliciously constructed web page containing crafted SVG elements, the browser's memory management system fails to properly track the lifecycle of allocated memory blocks. This mismanagement creates opportunities for attackers to overwrite freed memory with malicious data, potentially leading to heap corruption. The flaw operates at the intersection of memory management and graphics rendering, where the SVG processing code does not adequately verify that referenced memory regions remain valid throughout the rendering process.
The operational impact of CVE-2019-5144 extends beyond simple memory corruption, as it provides potential for arbitrary code execution within the context of the browser process. Attackers can leverage this vulnerability to execute malicious payloads on targeted systems, potentially leading to full system compromise. The attack surface is limited to users visiting malicious web pages, making this vulnerability particularly dangerous in phishing campaigns or compromised websites. The vulnerability's exploitation requires no user interaction beyond simply opening the malicious page, making it a significant threat vector. This characteristic aligns with ATT&CK technique T1203 which describes exploitation of web applications through browser-based attacks, where the initial compromise occurs through web page rendering rather than traditional software exploitation methods.
Mitigation strategies for this vulnerability primarily involve immediate software updates to patched versions of Safari and WebKit. Apple released security updates addressing this specific flaw, and users should maintain current versions of their browsers to prevent exploitation. Additionally, implementing browser security features such as memory protection mechanisms, sandboxing, and strict content security policies can reduce the impact of potential exploitation attempts. Network-level defenses including web application firewalls and content filtering systems may help detect and block malicious SVG content. Organizations should also consider implementing user education programs to recognize potentially malicious web content and maintain regular security assessments to identify similar vulnerabilities in their browser configurations. The remediation process should include comprehensive testing of patched versions to ensure that the vulnerability is properly addressed without introducing regressions in legitimate web functionality.