CVE-2019-13720 is an use-after-free vulnerability in Google Chrome WebAudio. CISA added it to the Known Exploited Vulnerabilities catalogue on 23 May 2022, which means attackers have used it in real attacks. Google Chrome WebAudio contains a use-after-free vulnerability that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page.
What a WebAudio use-after-free means
A use-after-free is a memory safety flaw, the program keeps using an object after it has already been released. In browser code, that can turn a normal webpage into a crash, corruption, or code execution path if the attacker can shape heap layout and timing.
WebAudio is a browser feature for creating, processing, and routing sound in web applications. When a flaw in that subsystem is reachable from a crafted HTML page, the browser’s multimedia parsing and runtime memory management become part of the attack surface, not just the visible page content.
Why this class of browser bug is dangerous
Browser use-after-free bugs are dangerous because they often move from instability to exploitable heap corruption. The attacker does not need local access, only a way to get the victim to load malicious content, and browser complexity gives them many opportunities to influence object lifetimes and reuse freed memory.
For a browser component like WebAudio, the practical concern is that media processing code tends to sit deep in complex object graphs. That makes lifetime mistakes harder to reason about and easier to turn into a reliable exploit when the attacker can repeatedly trigger the vulnerable path.
How organisations assess exposure
Exposure starts with knowing where Chrome is installed and which channels or managed update streams are in use, because browser vulnerabilities are often widespread but unevenly remediated. Teams should confirm whether the affected version is present on managed desktops, VDI images, kiosks, and developer systems that may browse untrusted content.
Authoritative version and fix details belong in the vendor advisory and the CVE Program record, while exploitation status is tracked in the NIST National Vulnerability Database and the Vulnerability Management Guide. For a browser flaw already added to CISA KEV, prioritisation should treat exposure as urgent rather than purely theoretical.
Remediation, detection, and post-incident review
The primary remediation is to remove the vulnerable browser build from circulation as quickly as possible. Where patching is delayed, organisations should reduce exposure by tightening web browsing to trusted content paths, limiting high-risk user sessions, and using compensating controls that reduce the chance of untrusted pages reaching the browser in the first place.
Detection should focus on abnormal browser crashes, suspicious renderer behaviour, and signs that a normal browsing session is being used as an exploit delivery path. After patching, review whether the browser process, user profile, or adjacent system activity shows signs of compromise beyond the crash itself, because successful exploitation can leave follow-on payloads, persistence, or credential theft in its wake.
Risk and Threat Considerations
Browser use-after-free flaws matter because they turn a routine visit to a malicious or compromised page into a remote exploitation path. In practice, the threat is not just a crash, but the chance that crafted content can trigger memory corruption and hand an attacker control of the browser process.
Failure mechanism: The attacker drives the vulnerable WebAudio path until freed memory is reused in a way that changes program flow or corrupts adjacent objects, which can make the exploit more reliable on repeated attempts.
Impact: Successful exploitation can lead to code execution in the browser context, followed by session theft, malicious downloads, or a broader compromise if the user profile or endpoint is already highly trusted.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while NIST SP 800-53 Rev 5, CIS Controls v8 and OWASP ASVS set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | SI-16 — Memory Protection | Browser memory corruption risk maps to protection against unsafe memory access and exploitation. |
| SI-3 — Malicious Code Protection | Exploit delivery through a crafted page requires defenses that reduce malicious content execution paths. | |
| SI-2 — Flaw Remediation | The CVE requires rapid correction and verification of vulnerable browser builds. | |
| Recommendation — Apply SI-16 controls to harden against memory corruption and unsafe object lifetime flaws. Use SI-3 to block or contain malicious content before it reaches the browser process. Use SI-2 to prioritize, deploy, and verify remediation for the affected browser version. | ||
| CIS Controls v8 | CIS-7 — Continuous Vulnerability Management | KEV-listed browser flaws require asset scoping, prioritization, and verification of fix status. |
| Recommendation — Use CIS-7 to identify exposed browser assets and accelerate remediation. | ||
| MITRE ATT&CK | T1189 — Drive-by Compromise | A crafted HTML page is a classic drive-by delivery path for browser exploitation. |
| Recommendation — Hunt for drive-by compromise activity that delivers malicious web content to targets. | ||
| OWASP ASVS | V12 — Secure Communication | Browser exploitation via hostile web content depends on unsafe handling of content over web channels. |
| Recommendation — Validate browser-facing content paths and transport assumptions under V12. | ||
Practitioner Guidance
Why practitioners should care: Browser vulnerabilities are high-volume, fast-moving exposure points because they affect many users at once and often sit outside traditional server patching workflows. Treat browser patching as an endpoint security and user-risk issue, not only a software update task.
What to watch for: Repeated crashes in the browser, especially around media or rendering-heavy pages, should be treated as a signal to investigate exploitation attempts and confirm the host is fully updated. If the endpoint handled sensitive sessions, review for follow-on account or token abuse after remediation.