CVE-2023-29536 in Thunderbird
Summary
by MITRE • 06/02/2023
An attacker could cause the memory manager to incorrectly free a pointer that addresses attacker-controlled memory, resulting in an assertion, memory corruption, or a potentially exploitable crash. This vulnerability affects Firefox < 112, Focus for Android < 112, Firefox ESR < 102.10, Firefox for Android < 112, and Thunderbird < 102.10.
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Analysis
by VulDB Data Team • 05/28/2026
This vulnerability represents a critical memory management flaw that can lead to arbitrary code execution through improper pointer handling during memory deallocation processes. The issue manifests when the memory manager incorrectly frees a pointer that references attacker-controlled memory regions, creating a condition where the system's memory management logic becomes compromised. Such vulnerabilities typically arise from insufficient validation of pointer values before deallocation operations, allowing malicious actors to manipulate the memory management flow and potentially execute malicious code. The vulnerability affects multiple Mozilla products including Firefox desktop and mobile browsers, Firefox ESR versions, and Thunderbird email client, indicating a widespread impact across the Mozilla ecosystem. This type of memory corruption vulnerability falls under the CWE-415 category of double free errors and is closely related to CWE-416 use after free conditions that are commonly exploited in browser-based attacks.
The operational impact of this vulnerability is severe as it can be exploited to achieve remote code execution on affected systems. When an attacker-controlled pointer is freed incorrectly, the memory manager may attempt to deallocate memory that has already been freed or is not properly allocated, leading to memory corruption that can be leveraged for privilege escalation. The crash condition can be triggered through various means including crafted web content, malicious email attachments, or manipulated network data that causes the browser to process attacker-controlled memory addresses. This vulnerability particularly affects web browsers because they frequently handle untrusted input data and must manage complex memory allocation patterns during page rendering and script execution. The potential for exploitation is heightened in modern browser environments where sandboxing mechanisms are bypassed through memory corruption primitives that allow attackers to gain code execution privileges.
Security practitioners should prioritize immediate patch deployment across all affected Mozilla products including Firefox versions less than 112, Focus for Android versions less than 112, Firefox ESR versions less than 102.10, and Thunderbird versions less than 102.10. The mitigation strategy should include implementing proper pointer validation before deallocation operations and strengthening memory management routines to prevent double-free conditions. Organizations should also consider deploying intrusion detection systems that monitor for suspicious memory allocation patterns and network traffic that may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically through PowerShell or command line interfaces that attackers might use to establish persistence after successful exploitation. Additionally, the vulnerability demonstrates characteristics of T1548.001 for abuse of privileges through privilege escalation techniques that exploit memory corruption to gain elevated system access. Regular security assessments and code reviews focusing on memory management practices should be implemented to prevent similar issues in future software releases.