CVE-2020-6796 in Firefox
Summary
by MITRE
A content process could have modified shared memory relating to crash reporting information, crash itself, and cause an out-of-bound write. This could have caused memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 73 and Firefox < ESR68.5.
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Analysis
by VulDB Data Team • 08/17/2025
This vulnerability represents a critical memory corruption issue within the firefox browser's crash reporting mechanism that could potentially enable remote code execution. The flaw exists in how firefox handles shared memory operations during crash scenarios, specifically affecting the content process that manages web page rendering and execution. When a crash occurs, firefox's crash reporting system attempts to collect and store crash information in shared memory segments that are accessible to multiple processes. The vulnerability arises from insufficient bounds checking when writing crash-related data to these shared memory regions, allowing an attacker to manipulate memory contents beyond allocated boundaries.
The technical nature of this vulnerability aligns with common software security flaws categorized under CWE-121, which deals with stack-based buffer overflow conditions, and CWE-787, which addresses out-of-bounds write vulnerabilities. The flaw operates at the intersection of memory management and process isolation, where the content process fails to properly validate memory access boundaries when interacting with shared crash reporting data structures. This type of vulnerability is particularly dangerous because it can be exploited during normal browsing operations when a malicious webpage triggers a crash scenario, potentially allowing an attacker to execute arbitrary code with the privileges of the firefox process. The vulnerability affects both regular firefox releases and the extended support release versions, indicating it was present across multiple product lines and persisted for an extended period.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a potential attack vector for privilege escalation and remote code execution. When exploited, the out-of-bound write could overwrite critical memory structures including function pointers, return addresses, or other control data within the firefox process. This memory corruption could lead to arbitrary code execution, allowing attackers to gain control over the affected system. The vulnerability is particularly concerning because it operates within the browser's crash handling mechanism, which is invoked during normal user activities, making exploitation relatively straightforward. Attackers could craft malicious web pages that trigger specific crash conditions, then leverage the memory corruption to execute malicious code, potentially leading to full system compromise.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected firefox versions to ensure users are running firefox 73 or later, and firefox ESR68.5 or later. Organizations should implement automated patch management systems to ensure all firefox installations are updated promptly. Additionally, browser hardening measures such as implementing address space layout randomization, stack canaries, and other exploit mitigations can reduce the effectiveness of potential exploitation attempts. Security teams should monitor for any reported exploitation attempts and consider implementing network-based intrusion detection systems to identify potential exploitation attempts. The vulnerability also highlights the importance of proper memory validation in complex software systems and underscores the need for regular security assessments of core browser components, particularly those involved in error handling and crash reporting mechanisms. This vulnerability serves as a reminder of the critical importance of secure coding practices and the potential consequences of memory safety issues in widely deployed software applications.