CVE-2022-45409 in Thunderbird
Summary
by MITRE • 12/22/2022
The garbage collector could have been aborted in several states and zones and <code>GCRuntime::finishCollection</code> may not have been called, leading to a use-after-free and potentially exploitable crash. This vulnerability affects Firefox ESR < 102.5, Thunderbird < 102.5, and Firefox < 107.
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Analysis
by VulDB Data Team • 01/23/2023
The vulnerability identified as CVE-2022-45409 represents a critical memory safety issue within the garbage collection mechanism of Mozilla's Firefox and Thunderbird applications. This flaw exists in the GCRuntime::finishCollection function which is responsible for properly cleaning up memory resources during garbage collection cycles. The vulnerability stems from improper handling of garbage collection states where the collection process could be terminated prematurely in multiple zones and execution states without ensuring proper cleanup operations are completed. This fundamental breakdown in the garbage collection protocol creates conditions where memory allocated to objects may be freed while still being referenced by other parts of the application, establishing a classic use-after-free condition that can be exploited by malicious actors.
The technical implementation of this vulnerability involves the garbage collector's state management system where multiple execution paths and memory zones can cause the collection process to abort before reaching the completion phase. When GCRuntime::finishCollection is not invoked properly, the memory management subsystem fails to properly dereference and clean up object references that were scheduled for deletion. This creates dangling pointers and memory regions that remain accessible but are no longer valid for use, allowing attackers to manipulate the memory layout and potentially execute arbitrary code. The issue affects specific versions of Firefox ESR and Thunderbird where the garbage collection logic was not properly hardened against premature termination scenarios, with the vulnerability being present in Firefox versions prior to 107 and Firefox ESR versions prior to 102.5, as well as Thunderbird versions before 102.5.
The operational impact of this vulnerability extends beyond simple application crashes to potentially enable remote code execution in targeted scenarios. Attackers can leverage the use-after-free condition to corrupt memory structures and manipulate the execution flow of the affected applications, particularly when combined with other exploitation techniques such as heap spraying or return-oriented programming. The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in memory management, and represents a significant risk to users who may encounter malicious web content or email attachments that trigger the problematic garbage collection path. This type of vulnerability is particularly dangerous in browser environments where attackers can leverage the complex memory management features to bypass modern security mitigations.
Mitigation strategies for CVE-2022-45409 require immediate patching of affected applications to the latest stable versions where the garbage collection logic has been properly fixed. System administrators should prioritize deployment of updates across all affected platforms, particularly in enterprise environments where browsers are widely used. The fix typically involves ensuring that GCRuntime::finishCollection is called consistently regardless of the garbage collection termination state, implementing proper state tracking mechanisms, and adding additional validation checks before memory deallocation operations. Security teams should monitor for exploitation attempts and consider implementing additional browser hardening measures such as address space layout randomization, stack canaries, and exploit prevention techniques. Organizations should also maintain awareness of related vulnerabilities in the same memory management subsystem and ensure comprehensive testing of patched versions to prevent regression issues that could introduce similar flaws. The ATT&CK framework categorizes this vulnerability under T1059.007 for command and scripting interpreter, as exploitation may involve crafting malicious content that triggers the memory corruption during garbage collection cycles.