CVE-2020-6545 in Chrome
Summary
by MITRE
Use after free in audio in Google Chrome prior to 84.0.4147.125 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/05/2025
The vulnerability identified as CVE-2020-6545 represents a critical use-after-free condition affecting Google Chrome's audio processing components. This flaw exists in versions prior to 84.0.4147.125 and allows remote attackers to potentially exploit heap corruption through maliciously crafted HTML pages. The vulnerability stems from improper memory management within Chrome's audio handling subsystem where freed memory locations are still being accessed or referenced, creating opportunities for arbitrary code execution.
The technical nature of this vulnerability aligns with CWE-416, which describes the use of freed memory condition where a program continues to reference memory that has already been freed. In Chrome's case, the audio processing pipeline fails to properly manage memory references when handling audio elements within web pages, leading to situations where freed memory blocks can be reallocated and subsequently accessed by malicious code. This particular flaw manifests when Chrome processes audio-related HTML elements such as audio tags, audio contexts, or Web Audio API calls that trigger the problematic code path.
The operational impact of CVE-2020-6545 extends beyond simple heap corruption, as it provides attackers with a potential pathway for remote code execution. When an attacker crafts a malicious HTML page containing specifically designed audio elements, the vulnerability can be triggered during normal browser operation. The attacker can leverage this condition to overwrite memory contents, potentially redirecting execution flow to malicious code. This type of vulnerability is particularly dangerous in browser environments where users frequently encounter untrusted content and where the attack surface includes complex audio processing APIs.
From an attack perspective, this vulnerability maps to several ATT&CK techniques including T1059 for command and scripting interpreter execution and T1070 for indicator removal. The exploitation process typically involves crafting HTML content that triggers the audio processing path, causing the use-after-free condition to manifest. Attackers may use this vulnerability in conjunction with other techniques such as sandbox escape or privilege escalation to gain deeper system access. The vulnerability's remote nature means that simply visiting a malicious webpage can trigger the exploit, making it particularly dangerous for end users.
The remediation for CVE-2020-6545 requires immediate patching of Chrome browsers to version 84.0.4147.125 or later, which includes memory management fixes in the audio processing components. Organizations should implement comprehensive browser update policies to ensure all systems receive the latest security patches. Additional mitigations include implementing strict content security policies, enabling sandboxing features, and deploying web application firewalls to filter malicious content. Security teams should also monitor for exploitation attempts through network traffic analysis and endpoint detection systems that can identify suspicious memory access patterns or unusual audio processing behaviors. The fix implemented by Google addresses the underlying memory management issue through improved reference counting and proper deallocation procedures within the audio processing subsystem.