A remote code execution vulnerability exists in the way affected Microsoft scripting engines render when handling objects in memory in Microsoft browsers. These vulnerabilities could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. This vulnerability is different from those described in CVE-2017-0010, CVE-2017-0015, CVE-2017-0032, CVE-2017-0035, CVE-2017-0067, CVE-2017-0071, CVE-2017-0094, CVE-2017-0131, CVE-2017-0132, CVE-2017-0133, CVE-2017-0134, CVE-2017-0136, CVE-2017-0137, CVE-2017-0138, CVE-2017-0141, CVE-2017-0150, and CVE-2017-0151.
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Edge | Microsoft | - (including) | - (including) |
The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:
In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.