Real Time Engineers FreeRTOS+FAT 160919a has a use after free. The function FF_Close() is defined in ff_file.c. The file handler pxFile is freed by ffconfigFREE, which (by default) is a macro definition of vPortFree(), but it is reused to flush modified file content from the cache to disk by the function FF_FlushCache().
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://sourceforge.net/p/freertos/bugs/199/ | third party advisory exploit |