CVE-2018-5093 in Firefox
Summary
by MITRE
A heap buffer overflow vulnerability may occur in WebAssembly during Memory/Table resizing, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 58.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 12/30/2019
The heap buffer overflow vulnerability identified as CVE-2018-5093 represents a critical security flaw in Mozilla Firefox browser versions prior to 58. This vulnerability specifically manifests during WebAssembly memory and table resizing operations, which are fundamental components of the WebAssembly execution environment. The issue arises from inadequate bounds checking within the browser's WebAssembly implementation, creating a scenario where maliciously crafted WebAssembly code can trigger memory corruption through improper heap management during dynamic resource allocation.
The technical flaw occurs when the WebAssembly engine attempts to resize memory or tables, leading to a situation where data is written beyond the allocated heap buffer boundaries. This heap-based memory corruption vulnerability falls under the CWE-121 category of Stack-based Buffer Overflow, though it manifests in heap memory due to the nature of WebAssembly's dynamic memory management. The vulnerability is particularly dangerous because it can be exploited through web-based attacks where attackers craft malicious WebAssembly modules that trigger the buffer overflow during normal execution flow, potentially allowing arbitrary code execution or complete browser compromise.
The operational impact of CVE-2018-5093 extends beyond simple browser crashes, as it represents a potential path to remote code execution within the context of the victim's browser. Attackers can leverage this vulnerability through drive-by downloads or malicious websites that serve specially crafted WebAssembly content. The exploitation process typically involves loading a malicious WebAssembly module that forces the browser to perform memory/table resizing operations with malicious parameters, causing the heap buffer overflow. This vulnerability aligns with ATT&CK technique T1059.007 for Web-based exploitation and represents a significant threat vector for credential theft, data exfiltration, and persistent compromise of user systems.
Mitigation strategies for CVE-2018-5093 primarily involve immediate browser updates to Firefox version 58 or later, where the vulnerability has been patched through enhanced bounds checking and memory management procedures. Security administrators should implement proactive measures including browser hardening configurations, content security policies, and regular vulnerability assessments. The patch addresses the root cause by implementing proper memory boundary validation during WebAssembly resizing operations and includes additional safeguards against similar heap corruption scenarios. Organizations should also consider deploying web application firewalls and monitoring systems to detect potential exploitation attempts, while maintaining updated threat intelligence feeds to identify malicious WebAssembly content that may attempt to leverage this vulnerability.