CVE-2016-5290 in Firefox
Summary
by MITRE
Memory safety bugs were reported in Firefox 49 and Firefox ESR 45.4. 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 Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.
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Analysis
by VulDB Data Team • 11/25/2025
The vulnerability identified as CVE-2016-5290 represents a critical memory safety issue affecting multiple Mozilla products including Firefox and Thunderbird. This vulnerability stems from memory safety bugs present in Firefox version 49 and Firefox ESR version 45.4, with similar impacts extending to Thunderbird versions prior to 45.5, Firefox ESR versions prior to 45.5, and Firefox versions prior to 50. The reported memory safety flaws constitute a serious concern within the cybersecurity landscape as they demonstrate evidence of memory corruption that could potentially be exploited by malicious actors.
Memory safety vulnerabilities of this nature typically arise from improper handling of memory allocation and deallocation within software applications. The specific bugs in question exhibit characteristics that suggest they could lead to memory corruption, which is a well-documented class of vulnerabilities that fall under CWE-122 - "Heap-based Buffer Overflow" and related memory corruption categories. These types of flaws occur when programs write beyond the boundaries of allocated memory regions, potentially allowing attackers to overwrite critical data structures or executable code. The vulnerability's potential for arbitrary code execution places it squarely within the domain of exploit development and represents a significant threat to system integrity.
The operational impact of CVE-2016-5290 extends beyond simple functionality degradation to encompass full system compromise potential. When memory corruption occurs in browser applications, attackers can leverage these flaws to execute malicious code with the privileges of the affected application. This creates a pathway for attackers to bypass security controls, escalate privileges, and potentially establish persistent access to affected systems. The vulnerability affects widely deployed software products, making it particularly dangerous as it could be exploited against a large number of users. According to ATT&CK framework category T1059, this vulnerability enables adversaries to execute code through compromised applications, while T1190 represents the technique of using vulnerabilities to gain initial access.
Mitigation strategies for CVE-2016-5290 should prioritize immediate patch deployment as the primary defense mechanism. Organizations must ensure all affected versions of Firefox, Thunderbird, and Firefox ESR are updated to their respective patched versions. Additionally, implementing network-based protections such as intrusion detection systems and web application firewalls can provide additional layers of defense. Browser hardening measures including disabling unnecessary plugins, implementing strict content security policies, and using sandboxing technologies can reduce the attack surface. Security monitoring should include detection of anomalous behavior patterns that might indicate exploitation attempts, particularly focusing on unusual memory access patterns or unexpected code execution within browser processes. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues before they can be exploited in the wild.