CVE-2017-7811 in Firefox
Summary
by MITRE
Memory safety bugs were reported in Firefox 55. 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 Firefox < 56.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/21/2019
The vulnerability identified as CVE-2017-7811 represents a critical memory safety issue within Mozilla Firefox version 55 and earlier, where multiple memory corruption flaws were discovered in the browser's codebase. These memory safety bugs constitute a significant security risk as they create potential entry points for malicious actors to execute arbitrary code on affected systems. The vulnerability specifically affects Firefox versions prior to 56, making it a time-sensitive concern for organizations still operating legacy browser installations. The presence of memory corruption evidence within these bugs indicates that the flaws could potentially be leveraged to gain unauthorized control over affected systems, making them particularly dangerous in enterprise environments where browser security is paramount.
The technical nature of these memory safety bugs falls under the category of heap corruption vulnerabilities, which are commonly classified as CWE-122 Heap-based Buffer Overflow and CWE-787 Out-of-bounds Write within the Common Weakness Enumeration framework. These types of vulnerabilities typically arise from improper bounds checking in memory allocation and deallocation operations, allowing attackers to overwrite adjacent memory locations and potentially manipulate program execution flow. The flaws likely stem from insufficient validation of user-supplied data or improper handling of memory management operations within Firefox's rendering engine or JavaScript interpreter, creating opportunities for attackers to craft malicious web content that triggers the memory corruption conditions.
The operational impact of CVE-2017-7811 extends beyond simple browser exploitation, as successful exploitation could enable attackers to execute arbitrary code with the privileges of the user running Firefox. This vulnerability aligns with ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, where attackers could leverage the memory corruption to inject and execute malicious JavaScript code that ultimately leads to system compromise. Organizations using affected Firefox versions face significant risk of data breaches, privilege escalation attacks, and potential lateral movement within their networks, particularly in environments where users have administrative privileges or access to sensitive systems. The vulnerability's exploitation potential makes it a prime target for advanced persistent threat actors and malware authors seeking to establish persistent access to compromised systems.
Mitigation strategies for CVE-2017-7811 primarily focus on immediate browser updates to Firefox 56 or later versions where these memory safety issues have been addressed through comprehensive code reviews and memory management improvements. Organizations should implement strict browser version control policies and ensure automatic update mechanisms are enabled to prevent legacy versions from remaining in use. Additional protective measures include deploying web application firewalls, implementing content security policies, and utilizing browser hardening techniques such as sandboxing and privilege separation to limit the potential impact of successful exploitation attempts. Security teams should also monitor for indicators of compromise related to this vulnerability and conduct regular vulnerability assessments to identify any remaining instances of affected browser versions within their network infrastructure.