A use-after-free in BigIntPrimitive addition in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by an attacker to leak raw data from Hermes VM’s heap. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Hermes | * | 2023-02-02 (excluding) |