CVE-2024-7652 in Thunderbird
Summary
by MITRE • 09/06/2024
An error in the ECMA-262 specification relating to Async Generators could have resulted in a type confusion, potentially leading to memory corruption and an exploitable crash. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13, and Thunderbird < 128.
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Analysis
by VulDB Data Team • 03/11/2025
The vulnerability described in CVE-2024-7652 represents a critical type confusion issue within the JavaScript engine of Mozilla's Firefox browser and Thunderbird email client. This flaw originates from an implementation error in the ECMA-262 specification governing async generators, which are asynchronous iterator functions that can pause and resume execution. The specification defines how async generators should handle their internal state management and value processing, but a discrepancy in the implementation creates opportunities for memory corruption through type confusion attacks. The vulnerability specifically impacts the JavaScript engine's handling of generator objects during asynchronous operations, where improper type validation allows attackers to manipulate object layouts in memory.
The technical exploitation of this vulnerability occurs when malicious JavaScript code leverages the flawed async generator implementation to cause objects of different types to be treated as the same type in memory. This type confusion allows attackers to overwrite memory locations with data of incorrect types, potentially leading to arbitrary code execution. The flaw manifests during the execution of async generator functions when the JavaScript engine fails to properly validate type information during state transitions. Attackers can craft specific JavaScript payloads that exploit this behavior by manipulating generator state during async operations, causing the engine to misinterpret memory contents and execute unintended code sequences.
The operational impact of this vulnerability extends across multiple Mozilla products including Firefox versions prior to 128, Firefox ESR versions prior to 115.13, and Thunderbird versions prior to 115.13 and 128. These applications are widely used across enterprise and consumer environments, making the vulnerability particularly dangerous as it affects both web browsing and email client functionality. The memory corruption resulting from type confusion can lead to various attack vectors including remote code execution, privilege escalation, and denial of service conditions. Security researchers have classified this as a high-severity issue due to its potential for exploitation in the wild and the broad attack surface it affects across multiple applications.
Mitigation strategies for CVE-2024-7652 primarily focus on immediate software updates to patched versions of affected applications. Mozilla has released security updates addressing this vulnerability, and users should immediately upgrade to Firefox 128, Firefox ESR 115.13, Thunderbird 115.13, or Thunderbird 128 respectively. Organizations should implement automated patch management systems to ensure all affected systems receive updates promptly. Additional defensive measures include implementing content security policies, enabling sandboxing features, and monitoring for suspicious JavaScript activity that might indicate exploitation attempts. The vulnerability aligns with CWE-122 (Heap Overflow) and CWE-125 (Out-of-bounds Read) categories, and maps to ATT&CK techniques including T1059.007 (JavaScript) and T1203 (Exploitation for Client Execution) in threat modeling frameworks. Security teams should also consider implementing network-based intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability pattern.