CVE-2023-5170 in Firefox
Summary
by MITRE • 10/25/2023
In canvas rendering, a compromised content process could have caused a surface to change unexpectedly, leading to a memory leak of a privileged process. This memory leak could be used to effect a sandbox escape if the correct data was leaked. This vulnerability affects Firefox < 118.
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Analysis
by VulDB Data Team • 10/25/2023
This vulnerability resides within firefox's canvas rendering subsystem where a memory leak occurs when a compromised content process manipulates surface data unexpectedly. The flaw represents a critical sandbox escape vector that could potentially allow attackers to gain elevated privileges by leveraging leaked memory contents from privileged processes. The vulnerability specifically impacts firefox versions prior to 118 where the canvas rendering engine fails to properly validate surface modifications that occur during content process execution. This issue stems from inadequate memory management controls within the graphics rendering pipeline, creating opportunities for malicious actors to exploit the memory leak for privilege escalation.
The technical implementation of this vulnerability involves a race condition or improper memory handling mechanism within firefox's multi-process architecture. When a content process attempts to modify canvas surfaces, the system fails to properly isolate or validate these operations against privileged memory regions. The memory leak occurs because the rendering engine does not properly clean up or restrict access to sensitive memory areas that contain privileged data structures. This flaw aligns with CWE-476 which addresses null pointer dereference vulnerabilities and CWE-122 which covers buffer overflow conditions in memory management. The vulnerability can be classified under ATT&CK technique T1068 which describes local privilege escalation through exploitation of software vulnerabilities.
The operational impact of this vulnerability extends beyond simple memory leaks to encompass full sandbox escape capabilities. An attacker who successfully exploits this flaw could potentially access privileged memory segments that contain sensitive data or control structures. This memory access could reveal information about the browser's internal state, process memory layouts, or security token values that would otherwise remain protected. The exploitation scenario typically requires an attacker to first compromise a content process through a separate vulnerability, then leverage the memory leak to gain access to privileged memory regions. The vulnerability affects firefox versions prior to 118 where the canvas rendering engine lacked proper memory isolation mechanisms. This creates a significant security risk in environments where firefox is used for browsing untrusted content, as the memory leak could be exploited to bypass the browser's security model entirely.
Mitigation strategies should focus on immediate version upgrades to firefox 118 or later where the vulnerability has been patched. Organizations should also implement additional security measures such as content security policies, sandbox hardening, and process isolation controls to limit the impact of potential exploitation. The patch addresses the underlying memory management issue by implementing proper validation of surface modifications and ensuring that privileged memory regions remain protected from unauthorized access. System administrators should monitor for exploitation attempts and consider implementing network-based intrusion detection systems to identify potential exploitation attempts targeting this vulnerability. Regular security updates and patch management processes become critical in preventing exploitation of this class of vulnerabilities that could enable complete system compromise through browser-based attacks.