CVE-2016-5289 in Firefox
Summary
by MITRE
Memory safety bugs were reported in Firefox 49. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 50.
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Analysis
by VulDB Data Team • 01/31/2018
The vulnerability identified as CVE-2016-5289 represents a critical memory safety issue within Mozilla Firefox version 49 and earlier, with implications extending to the broader web browser security landscape. This flaw emerged as part of a broader category of vulnerabilities affecting the Firefox browser ecosystem, specifically targeting the underlying memory management systems that govern how applications handle dynamic memory allocation and deallocation. The vulnerability stems from multiple memory safety bugs that were discovered during routine security audits and code reviews of the browser's rendering engine and JavaScript engine components. These memory safety issues are particularly concerning because they manifest as memory corruption vulnerabilities that could potentially be leveraged by malicious actors to execute arbitrary code on affected systems.
The technical nature of CVE-2016-5289 involves fundamental memory management flaws that occur when the browser processes certain web content or executes specific JavaScript operations. These memory safety bugs typically arise from improper handling of memory allocation, buffer overflows, or use-after-free conditions that occur within the browser's core components. When these conditions are triggered through malicious web content, they can cause the browser to write data to memory locations where it should not have access, leading to unpredictable behavior and potential system compromise. The vulnerability's classification aligns with common CWE entries such as CWE-121 for stack-based buffer overflow and CWE-122 for heap-based buffer overflow, which are standard indicators of memory corruption vulnerabilities. The specific nature of these bugs suggests that they may have originated from insufficient bounds checking or improper memory deallocation practices within Firefox's JavaScript engine and rendering components.
The operational impact of CVE-2016-5289 extends far beyond simple browser instability, as the potential for remote code execution creates significant security risks for users who browse the internet. Attackers could exploit these vulnerabilities by crafting malicious web pages that trigger the memory corruption conditions when loaded in vulnerable Firefox versions, potentially allowing them to execute arbitrary code with the privileges of the browser process. This capability represents a severe threat vector because it enables attackers to bypass traditional security measures and gain control over affected systems without requiring user interaction beyond visiting a malicious website. The vulnerability's exploitability is further enhanced by the fact that modern web browsers like Firefox are designed to run complex JavaScript code from untrusted sources, making the memory corruption issues particularly dangerous. The potential for privilege escalation and persistent system compromise makes this vulnerability particularly attractive to threat actors, as demonstrated by the numerous exploitation attempts observed in the wild.
Mitigation strategies for CVE-2016-5289 primarily focus on immediate remediation through software updates and browser version upgrades to Firefox 50 or later versions where these memory safety issues have been addressed. Organizations should implement comprehensive patch management procedures to ensure all affected Firefox installations are updated promptly, as the vulnerability affects the entire Firefox 49 release line and earlier versions. Additionally, security teams should consider implementing browser hardening measures such as enabling sandboxing features, restricting JavaScript execution in sensitive contexts, and deploying web application firewalls to monitor and filter potentially malicious content. The vulnerability's characteristics align with ATT&CK tactics such as T1059 for command and scripting interpreter and T1078 for valid accounts, indicating that successful exploitation could enable attackers to establish persistent access and execute malicious commands. Organizations should also conduct regular security assessments to identify any remaining instances of vulnerable Firefox installations and maintain continuous monitoring for exploitation attempts targeting this specific vulnerability. The remediation process should include verifying that all users have upgraded to patched versions and that appropriate security configurations are in place to minimize the risk of successful exploitation attempts.