CVE-2024-5694

What it actually does

Use-after-free in the JavaScript engine allowing an attacker to read memory contents from the JavaScript string section of the heap.

Why it matters to the business

Attackers could read sensitive data such as credentials or session tokens from browser memory, raising the risk of account takeover or data exposure for users of affected browsers; low exploit likelihood limits immediate widespread impact but still requires prompt patching.

How an attack unfolds

An attacker hosts a malicious webpage with crafted JavaScript that triggers the use-after-free condition during object lifecycle handling, then reads and exfiltrates memory contents from the JS heap.

How to fix it

Upgrade all Firefox installations to version 127 or later as soon as possible.

How to confirm the fix worked

Confirm installed Firefox version is 127 or higher; retest affected JavaScript scenarios in updated builds to verify absence of the use-after-free.

Typical attack path

1. Attacker prepares malicious webpage containing trigger JavaScript
2. Victim is directed to or visits the page via browser
3. Script executes and triggers use-after-free during memory management
4. Attacker reads arbitrary memory in the JS string heap
5. Data is exfiltrated or used for further attacks

How to detect it

Examine browser process crash dumps and memory access logs for anomalous JavaScript heap activity; review web proxy or endpoint logs for visits to suspicious domains around the time of potential exploitation.

What your security team should do

• Prioritize browser updates across all endpoints within the next patch cycle
• Enable automatic updates for Firefox where possible
• Review and enforce browser version policies via endpoint management
• Monitor vendor advisories for any follow-on fixes or related issues