CVE-2018-5180 in Firefox
Summary
by MITRE
A use-after-free vulnerability can occur during WebGL operations. While this results in a potentially exploitable crash, the vulnerability is limited because the memory is freed and reused in a brief window of time during the freeing of the same callstack. This vulnerability affects Firefox < 60.
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Analysis
by VulDB Data Team • 07/20/2024
The CVE-2018-5180 vulnerability represents a critical use-after-free condition that manifests during WebGL operations within the Firefox browser. This type of vulnerability falls under the CWE-416 category, which specifically addresses the use of freed memory, making it a fundamental memory safety issue. The flaw occurs when WebGL context objects are manipulated in a manner that allows for memory deallocation followed by subsequent access to the same memory location, creating a window where the freed memory can be reused before the original reference is properly invalidated.
The technical implementation of this vulnerability involves the WebGL rendering pipeline where objects are allocated and subsequently freed during the normal operation of graphics processing. When the WebGL context undergoes operations that trigger memory deallocation, there exists a brief temporal window during which the freed memory can be accessed by malicious code. This temporal window is typically measured in microseconds and occurs within the same call stack execution path, making exploitation particularly challenging but not impossible. The vulnerability specifically affects Firefox versions prior to 60, indicating that this was a targeted issue within a particular release cycle where memory management routines were not properly synchronized.
The operational impact of CVE-2018-5180 extends beyond simple browser instability, as it creates a potential exploitation vector for remote code execution attacks. While the memory reuse window is limited, it provides sufficient opportunity for attackers to craft payloads that can manipulate the freed memory before it is overwritten. This vulnerability aligns with ATT&CK technique T1059.007, which covers the execution of malicious code through browser-based attacks, and demonstrates how graphics rendering subsystems can become attack surfaces. The limited window of exploitation does not prevent successful exploitation, as attackers can leverage various techniques such as heap spraying or precise timing to ensure successful memory corruption.
Mitigation strategies for this vulnerability primarily involve upgrading to Firefox version 60 or later, where the memory management routines have been properly addressed. The fix implemented by Mozilla likely involved strengthening the synchronization mechanisms within the WebGL context handling code to prevent the conditions that lead to the use-after-free scenario. Security researchers should monitor for similar patterns in other graphics libraries and rendering engines, as this vulnerability type often appears in complex memory management scenarios. Organizations should implement automated patch management systems to ensure timely deployment of browser security updates, particularly given that this vulnerability could enable full system compromise through browser-based attacks. The vulnerability also highlights the importance of continuous security testing in graphics rendering components, as these areas often receive less scrutiny compared to core browser functionality.