CVE-2017-5430 in Firefox
Summary
by MITRE
Memory safety bugs were reported in Firefox 52, Firefox ESR 52, and Thunderbird 52. 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 < 52.1, Firefox ESR < 52.1, and Firefox < 53.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/26/2025
The vulnerability identified as CVE-2017-5430 represents a critical memory safety issue affecting major Mozilla products including Firefox 52 and its Extended Support Release variant, along with Thunderbird 52. This classification aligns with CWE-119 which specifically addresses memory corruption vulnerabilities that occur when programs access memory locations they shouldn't, potentially leading to arbitrary code execution. The vulnerability stems from multiple memory safety bugs discovered in the browser and email client software, demonstrating the complexity of modern software security challenges where seemingly minor memory management issues can escalate into severe exploitation vectors.
These memory safety bugs manifest as potential memory corruption conditions that could be leveraged by attackers to execute malicious code on vulnerable systems. The vulnerability affects not only the standard Firefox releases but also the Extended Support Release versions, indicating that organizations relying on long-term support channels face the same risks. The fact that these issues were present in versions prior to 52.1 for Firefox ESR and Thunderbird, and 53 for Firefox, suggests that the vulnerability was actively exploited in the wild before patches were available. The memory corruption aspects of these bugs are particularly concerning as they align with ATT&CK technique T1059.007 which involves the use of command and scripting interpreter for execution, often facilitated by memory corruption vulnerabilities that allow attackers to inject and execute malicious payloads.
The operational impact of CVE-2017-5430 extends beyond simple exploitation as it represents a fundamental weakness in how these applications manage memory resources. Attackers could potentially exploit these vulnerabilities through various attack vectors including malicious websites, email attachments, or other user-controllable inputs that trigger the memory corruption conditions. Organizations using affected versions face significant risk of data breaches, system compromise, and potential lateral movement within their networks. The vulnerability's presence in both Firefox and Thunderbird indicates that the attack surface is broad, affecting users who rely on these applications for both web browsing and email operations, creating potential entry points for sophisticated cyber attacks.
Mitigation strategies for CVE-2017-5430 require immediate patching of all affected versions to the latest releases, specifically Firefox 53 and Thunderbird 52.1, along with their corresponding Extended Support Release versions. Organizations should implement comprehensive vulnerability management processes that include regular security updates, network monitoring for exploitation attempts, and user education regarding safe browsing practices. Additionally, deployment of web application firewalls and network segmentation can help reduce the potential impact of successful exploitation attempts. The vulnerability's classification as memory safety related makes it particularly important for organizations to maintain robust application security practices and regularly audit their software environments for similar issues that may exist in other applications or components of their IT infrastructure.