CVE-2020-12426 in Firefox
Summary
by MITRE
Mozilla developers and community members reported memory safety bugs present in Firefox 77. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 78.
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Analysis
by VulDB Data Team • 07/10/2020
This vulnerability represents a critical memory safety issue discovered in Mozilla Firefox version 77 and earlier, highlighting the ongoing challenges in web browser security. The flaw emerged from the complex interaction between Firefox's rendering engine and memory management systems, where multiple memory safety bugs were identified through extensive code review and security testing by both Mozilla developers and the broader security community. These bugs specifically affected Firefox versions prior to 78, creating a window of opportunity for potential exploitation that could have led to arbitrary code execution on affected systems.
The technical nature of this vulnerability stems from memory corruption flaws within Firefox's core components, particularly in how the browser handles memory allocation and deallocation during web page rendering and JavaScript execution. When these memory safety issues are triggered, they can result in unpredictable behavior including buffer overflows, use-after-free conditions, or other memory corruption scenarios that fundamentally compromise the browser's stability and security boundaries. The presence of memory corruption vulnerabilities creates opportunities for attackers to manipulate memory contents in ways that could bypass security mechanisms and execute malicious code with the privileges of the browser process.
The operational impact of this vulnerability extends beyond simple browser instability, as it represents a potential pathway for sophisticated attacks that could compromise user systems. Attackers could potentially leverage these memory corruption flaws through malicious websites or web content to execute arbitrary code remotely, effectively bypassing traditional security controls and potentially gaining full system access. The vulnerability's severity is underscored by the fact that these bugs were identified as having evidence of memory corruption, indicating that they could be reliably exploited to achieve arbitrary code execution rather than merely causing crashes or instability. This type of vulnerability directly affects the core security model of web browsers, which are designed to isolate web content execution from the underlying operating system.
Mitigation strategies for this vulnerability require immediate patching of affected Firefox installations to version 78 or later, where the memory safety issues have been addressed through code modifications and memory management improvements. Organizations should prioritize updating their Firefox deployments and consider implementing additional security measures such as browser hardening configurations, content security policies, and regular security assessments. The vulnerability aligns with common weakness enumerations such as CWE-121 for stack-based buffer overflow and CWE-122 for heap-based buffer overflow, while also mapping to attack techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1203 for exploitation for privilege escalation. Regular security monitoring and vulnerability management programs should ensure that such memory safety issues are identified and patched promptly to prevent exploitation in production environments.