In the __mdiff function of the newlib libc library, all versions prior to 3.3.0 (see newlib/libc/stdlib/mprec.c), Balloc is used to allocate big integers, however no check is performed to verify if the allocation succeeded or not. The access to _wds and _sign will trigger a null pointer dereference bug in case of a memory allocation failure.
Weakness
The product dereferences a pointer that it expects to be valid but is NULL.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Newlib | Newlib_project | * | 3.3.0 (excluding) |
| Gcc-snapshot | Ubuntu | bionic | * |
| Gcc-snapshot | Ubuntu | trusty | * |
| Gcc-snapshot | Ubuntu | xenial | * |
| Newlib | Ubuntu | bionic | * |
| Newlib | Ubuntu | eoan | * |
| Newlib | Ubuntu | esm-apps/bionic | * |
| Newlib | Ubuntu | esm-apps/xenial | * |
| Newlib | Ubuntu | groovy | * |
| Newlib | Ubuntu | hirsute | * |
| Newlib | Ubuntu | impish | * |
| Newlib | Ubuntu | kinetic | * |
| Newlib | Ubuntu | trusty | * |
| Newlib | Ubuntu | upstream | * |
| Newlib | Ubuntu | xenial | * |