CVE-2017-5441 in Firefox
Summary
by MITRE
A use-after-free vulnerability when holding a selection during scroll events. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.
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Analysis
by VulDB Data Team • 11/26/2025
The vulnerability described in CVE-2017-5441 represents a critical use-after-free condition that occurs within Mozilla's browser and email client implementations when handling selection states during scrolling operations. This flaw resides in the core rendering and event handling mechanisms of the affected software components, specifically within the Gecko engine that powers Firefox and Thunderbird applications. The vulnerability manifests when the application attempts to access memory that has already been freed, creating a potential pathway for malicious exploitation through controlled crash conditions.
The technical implementation of this vulnerability stems from improper memory management during the interaction between user selection operations and scroll event processing. When a user selects text and simultaneously scrolls through content, the application's internal data structures become inconsistent, leading to scenarios where pointers reference deallocated memory regions. This condition is particularly dangerous because it occurs in the context of user interaction, making exploitation more feasible through social engineering or targeted attacks. The vulnerability falls under CWE-416, which specifically addresses use-after-free conditions in software implementations, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage in exploitation contexts.
The operational impact of this vulnerability extends beyond simple application instability, as it creates opportunities for remote code execution when successfully exploited. Attackers can potentially craft malicious web content or email messages that trigger the vulnerable code path during normal user operations, leading to arbitrary code execution with the privileges of the affected application. This makes the vulnerability particularly concerning for enterprise environments where users may encounter malicious content through web browsing or email interactions. The affected versions represent a broad range of Mozilla products including Thunderbird email clients and various Firefox releases, indicating the widespread nature of the memory management flaw.
Mitigation strategies for CVE-2017-5441 require immediate patch application to all affected versions, as the vulnerability cannot be effectively addressed through configuration changes or workarounds. Organizations should prioritize updating Firefox ESR versions to 45.9, 52.1, and newer releases, while ensuring Thunderbird installations reach version 52.1 or higher. Security teams should implement network monitoring to detect potential exploitation attempts targeting this vulnerability, particularly focusing on unusual browser behavior or crash patterns. Additionally, user education regarding safe browsing practices and email handling remains crucial, as the vulnerability can be triggered through social engineering attacks that present malicious content to unsuspecting users during normal interaction patterns.