CVE-2017-18269

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-05-18 · updated 2026-06-17
Weakness: CWE-119

Description

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.

Affected products

GNU C Library (glibc): from 2.21 through 2.27

References

https://github.com/fingolfin/memmove-bug
https://security.netapp.com/advisory/ntap-20190329-0001/
https://security.netapp.com/advisory/ntap-20190401-0001/
https://sourceware.org/bugzilla/show_bug.cgi?id=22644
https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=cd66c0e584c6d692bc8347b5e72723d02b8a8ada
https://usn.ubuntu.com/4416-1/
https://github.com/fingolfin/memmove-bug
https://security.netapp.com/advisory/ntap-20190329-0001/
https://security.netapp.com/advisory/ntap-20190401-0001/
https://sourceware.org/bugzilla/show_bug.cgi?id=22644
https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=cd66c0e584c6d692bc8347b5e72723d02b8a8ada
https://usn.ubuntu.com/4416-1/

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