CVE-2022-42928

What it actually does

Certain types of allocations were missing annotations that, if the Garbage Collector was in a specific state, could have lead to memory corruption and a potentially exploitable crash.

Why it matters to the business

Remote attackers could crash the application or achieve code execution, risking data exposure, system compromise, and operational disruption across widely deployed client software.

How an attack unfolds

An attacker crafts content that triggers the unannotated allocation pattern while the garbage collector reaches the vulnerable state, turning the resulting memory corruption into arbitrary code execution.

How to fix it

Upgrade Firefox to 106 or later, Firefox ESR to 102.4 or later, and Thunderbird to 102.4 or later.

How to confirm the fix worked

Confirm installed versions meet or exceed the fixed releases and monitor crash reports for the previously observed allocation pattern.

Typical attack path

1. Serve malicious webpage or email to the target user
2. Trigger the allocation sequence that interacts with the garbage collector
3. Trigger the specific GC state to induce memory corruption
4. Leverage the corruption for code execution or denial of service

How to detect it

Inspect browser crash logs and memory dumps for allocation patterns matching the vulnerable garbage-collector state; correlate with web-request or email-delivery timestamps.

What your security team should do

• Apply updates to all affected Firefox, ESR, and Thunderbird instances without delay
• Review endpoint update policies to reduce time-to-patch windows
• Enable crash reporting and review logs for memory-corruption signatures