CVE-2016-5256 in Firefox
Summary
by MITRE
Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 49.0 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors.
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Analysis
by VulDB Data Team • 09/20/2022
The vulnerability identified as CVE-2016-5256 represents a critical security flaw within the browser engine of Mozilla Firefox versions prior to 49.0. This issue falls under the category of unspecified vulnerabilities, indicating that the exact nature of the flaws within the browser engine remains partially obscured from the initial description. The affected browser engine components are responsible for processing web content and rendering web pages, making them prime targets for exploitation. These vulnerabilities exist in the core rendering and processing mechanisms that handle various web technologies and protocols, potentially affecting the entire browser functionality.
The technical exploitation of these unspecified vulnerabilities leads to severe consequences including memory corruption and application crashes, which manifest as denial of service conditions. Memory corruption occurs when malicious code manipulates memory locations in ways that compromise the application's stability and integrity. The vulnerability's potential for arbitrary code execution places it in a particularly dangerous category, as attackers could potentially gain control over the affected system. These issues are classified under CWE-119 as memory corruption vulnerabilities and may align with CWE-787 for out-of-bounds writes or CWE-79 for cross-site scripting conditions depending on specific exploitation vectors. The attack surface is broad given that these vulnerabilities reside within the browser engine itself, which processes all web content from various sources.
The operational impact of CVE-2016-5256 extends beyond simple service disruption to potentially enable full system compromise. When exploited, these vulnerabilities allow remote attackers to cause applications to crash or behave unpredictably, creating denial of service conditions that can disrupt user productivity and business operations. The potential for arbitrary code execution transforms this vulnerability into a serious threat that could lead to data breaches, system compromise, or further lateral movement within networks. According to ATT&CK framework, this vulnerability would map to techniques such as T1059 for command and script interpreter execution and T1499 for network denial of service. The attack vectors likely involve malicious web pages or content that trigger the vulnerable browser engine components, potentially through crafted HTML, JavaScript, or other web technologies that exploit the memory corruption flaws.
Mitigation strategies for CVE-2016-5256 primarily focus on immediate patching and updating to Firefox version 49.0 or later, which contains the necessary security fixes. Organizations should implement comprehensive patch management procedures to ensure all browsers are updated promptly. Network security measures such as web application firewalls and content filtering systems can provide additional protection layers, though they may not prevent exploitation of such fundamental browser engine vulnerabilities. Security awareness training for users about avoiding suspicious web content and phishing attempts remains crucial. Regular security assessments and vulnerability scanning should include checks for outdated browser versions. The vulnerability's nature suggests that attackers may leverage it as part of multi-stage attacks, making layered defense strategies essential. System hardening practices including disabling unnecessary browser features and maintaining updated security configurations can reduce the attack surface. Organizations should also consider implementing browser isolation techniques and sandboxing mechanisms to contain potential exploitation attempts and limit the impact of successful attacks.