CVE-2022-38475

What it actually does

Allows writing a value to the first element of a zero-length JavaScript array without accessing an invalid memory address, bypassing intended bounds checks in the JavaScript engine.

Why it matters to the business

May enable attackers to corrupt application state or bypass security controls in web applications, leading to data integrity issues or unauthorized actions for users of affected browsers.

How an attack unfolds

An attacker serves a crafted web page containing malicious JavaScript that triggers the array write flaw to manipulate memory or bypass protections; no named threat actors or ransomware campaigns are associated.

How to fix it

Update Mozilla Firefox to version 104 or later on all affected systems.

How to confirm the fix worked

Confirm installed Firefox version is 104 or higher; attempt reproduction with boundary-testing JavaScript arrays in a controlled environment.

Typical attack path

1. Host a malicious webpage targeting vulnerable Firefox versions
2. Lure a user to visit the page via phishing or compromised sites
3. Execute JavaScript that performs the zero-length array write
4. Leverage the resulting state to achieve further unauthorized actions or corruption

How to detect it

Inspect browser process logs, crash reports, or JavaScript execution traces for unusual array write operations; no public exploit artifacts or threat actor IOCs are known.

What your security team should do

• Immediately deploy Firefox 104 or newer across the environment
• Enforce automatic browser updates via policy where possible
• Review web proxy or EDR logs for anomalous JavaScript behavior targeting array operations