CVE-2013-1738 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the JS_GetGlobalForScopeChain function in Mozilla Firefox before 24.0, Thunderbird before 24.0, and SeaMonkey before 2.21 allows remote attackers to execute arbitrary code by leveraging incorrect garbage collection in situations involving default compartments and frame-chain restoration.
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Analysis
by VulDB Data Team • 05/25/2021
The CVE-2013-1738 vulnerability represents a critical use-after-free flaw in Mozilla's JavaScript engine that affected multiple browser products including Firefox versions prior to 24.0, Thunderbird versions prior to 24.0, and SeaMonkey versions prior to 2.21. This vulnerability resides within the JS_GetGlobalForScopeChain function which is responsible for managing JavaScript execution contexts and scope chains during program execution. The flaw specifically manifests during garbage collection processes when default compartments and frame-chain restoration mechanisms interact inappropriately, creating conditions where freed memory objects can be accessed and manipulated by malicious actors.
The technical root cause of this vulnerability stems from improper memory management during JavaScript execution, particularly when dealing with compartmentalized execution environments. When JavaScript code executes within Firefox's engine, it creates various execution contexts and scope chains that are managed through compartmentalized memory structures. The flaw occurs when the garbage collector incorrectly handles memory cleanup in scenarios involving default compartments, where objects that should be freed remain accessible in memory due to improper reference tracking. This memory corruption allows attackers to manipulate freed memory locations and potentially execute arbitrary code with the privileges of the compromised browser process.
The operational impact of this vulnerability is severe and highly exploitable in remote attack scenarios. Attackers can craft malicious web pages that, when loaded in vulnerable browsers, trigger the specific conditions leading to the use-after-free condition. The vulnerability enables remote code execution without requiring user interaction beyond visiting a malicious website, making it particularly dangerous for widespread exploitation. The attack vector leverages JavaScript execution within the browser's rendering engine, where the attacker can manipulate the garbage collection timing and memory layout to overwrite critical memory structures with malicious payloads. This type of vulnerability aligns with CWE-416 which specifically addresses use-after-free conditions, and represents a classic example of how improper memory management can lead to privilege escalation and system compromise.
The exploitation of this vulnerability requires careful crafting of JavaScript code that can trigger the specific interaction between default compartments and frame-chain restoration during garbage collection cycles. Security researchers have documented that attackers can leverage this flaw to execute arbitrary code remotely, potentially leading to full system compromise. The vulnerability's impact extends beyond simple code execution as it can be used to bypass security mechanisms such as address space layout randomization and data execution prevention. Organizations should implement immediate mitigations including updating to patched versions of Firefox, Thunderbird, and SeaMonkey, as well as deploying network-based protections and monitoring for suspicious JavaScript behavior. The ATT&CK framework categorizes this vulnerability under privilege escalation and code execution techniques, specifically targeting the execution phase where adversaries establish persistence and maintain access to compromised systems.