CVE-2018-8139

Existe una vulnerabilidad de ejecución remota de código que se manifiesta en la forma en la que el motor de scripting gestiona los objetos en la memoria en Microsoft Edge. Esto también se conoce como "Scripting Engine Memory Corruption Vulnerability". Esto afecta a Microsoft Edge y ChakraCore. El ID de este CVE es diferente de CVE-2018-0945, CVE-2018-0946, CVE-2018-0951, CVE-2018-0953, CVE-2018-0954, CVE-2018-0955, CVE-2018-1022, CVE-2018-8114, CVE-2018-8122, CVE-2018-8128 y CVE-2018-8137.

Microsoft Edge Chakra JIT suffers from a bug. BoundFunction::NewInstance is used to handle calls to a bound function. The method first allocates a new argument array and copies the prepended arguments and others into the new argument array and calls the actual function. The problem is, it doesn't care about the CallFlags_NewTarget flag which indicates that there's an extra argument (new.target) at the end of the argument array. So the size of the new argument array created with the CallFlags_NewTarget flag will be always 1 less then required, this leads to an out-of-bounds read.