CVE-2016-5281 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the DOMSVGLength class in Mozilla Firefox before 49.0 and Firefox ESR 45.x before 45.4 allows remote attackers to execute arbitrary code by leveraging improper interaction between JavaScript code and an SVG document.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 09/20/2022
The CVE-2016-5281 vulnerability represents a critical use-after-free flaw within the DOMSVGLength class of Mozilla Firefox browser implementations. This vulnerability affects versions prior to Firefox 49.0 and Firefox ESR 45.x versions before 45.4, creating a significant security risk for users operating these older browser versions. The flaw manifests through improper interaction between JavaScript code and SVG documents, enabling malicious actors to exploit the memory management error in ways that can lead to complete system compromise.
The technical root cause of this vulnerability lies in the improper handling of memory references within the SVG DOM implementation. When JavaScript code interacts with SVG elements through the DOMSVGLength class, the browser fails to properly manage the lifecycle of memory objects, creating opportunities for attackers to manipulate freed memory locations. This use-after-free condition occurs when the browser attempts to access memory that has already been deallocated, allowing for potential code execution through carefully crafted malicious SVG content. The vulnerability specifically exploits the interaction between JavaScript's dynamic memory management and the SVG rendering engine's object lifetime management, creating a dangerous intersection point where memory corruption can be leveraged for arbitrary code execution.
The operational impact of CVE-2016-5281 extends far beyond simple browser exploitation, as it provides attackers with a pathway to achieve remote code execution on vulnerable systems. Attackers can craft malicious SVG documents that, when loaded by an affected Firefox browser, trigger the use-after-free condition and subsequently execute arbitrary code with the privileges of the browser process. This capability enables attackers to perform various malicious activities including data theft, system reconnaissance, privilege escalation, and deployment of additional malware. The vulnerability's remote nature means that users can be compromised simply by visiting a malicious website or opening a specially crafted email attachment containing the malicious SVG content. The attack vector is particularly dangerous because it leverages common web technologies that are frequently encountered in everyday browsing activities.
This vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in memory management, and demonstrates how improper object lifecycle management can create severe security implications. The attack pattern follows typical exploit development techniques that map to ATT&CK tactics including execution through web-based attacks and privilege escalation. Organizations affected by this vulnerability should prioritize immediate patching of all Firefox installations to prevent exploitation, as the window for exploitation remains open for systems running vulnerable versions. Security teams should also implement network-based protections such as web application firewalls and content filtering to mitigate the risk of exploitation, while monitoring for indicators of compromise related to this specific vulnerability. The remediation process requires careful attention to ensure that all instances of Firefox ESR 45.x and Firefox 48.x are updated to their patched versions, as partial updates may leave systems vulnerable to this particular use-after-free condition.