CVE-2017-18269

An SSE2-optimized memmove implementation for i386 in sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S in the GNU C Library (aka glibc or libc6) 2.21 through 2.27 does not correctly perform the overlapping memory check if the source memory range spans the middle of the address space, resulting in corrupt data being produced by the copy operation. This may disclose information to context-dependent attackers, or result in a denial of service, or, possibly, code execution.

This issue did not affect the versions of glibc and compat-glibc as shipped with Red Hat Enterprise Linux 5, 6 and 7 as they did not include the vulnerable code.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.