An exploitable signed comparison vulnerability exists in the ARMv7 memcpy() implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets that utilize the GNU glibc implementation) with a negative value for the 'num' parameter results in a signed comparison vulnerability. If an attacker underflows the 'num' parameter to memcpy(), this vulnerability could lead to undefined behavior such as writing to out-of-bounds memory and potentially remote code execution. Furthermore, this memcpy() implementation allows for program execution to continue in scenarios where a segmentation fault or crash should have occurred. The dangers occur in that subsequent execution and iterations of this code will be executed with this corrupted data.
Created glibc tracking bugs for this issue:
Affects: fedora-all [bug 1820332]
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):
Red Hat Enterprise Linux only supports the 64-bit ARM architecture (AArch64) which does not include the vulnerable implementation of `memcpy()`. Therefore, all versions of glibc as shipped with RHEL are not affected by this flaw.