CVE-2017-5972

Description

The TCP stack in the Linux kernel 3.x does not properly implement a SYN cookie protection mechanism for the case of a fast network connection, which allows remote attackers to cause a denial of service (CPU consumption) by sending many TCP SYN packets, as demonstrated by an attack against the kernel-3.10.0 package in CentOS Linux 7. NOTE: third parties have been unable to discern any relationship between the GitHub Engineering finding and the Trigemini.c attack code.

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗

Release	Package	Fixed in	Advisory
Debian 14	linux	4.4.2-1	—
Debian 13	linux	4.4.2-1	—
Debian 12	linux	4.4.2-1	—

Ubuntu

Security tracker ↗

Release	Package	Fixed in	Advisory
Ubuntu 24.04 LTS	linux-raspi-realtime	No fix yet	—
Ubuntu 22.04 LTS	linux-riscv +2	No fix yet	—
Ubuntu 20.04 LTS	linux-gke +5	No fix yet	—

Show 1 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
Ubuntu Pro 14.04 LTS	linux	No fix yet	—

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

Exploit-DB 1

Linux Kernel 3.10.0 (CentOS 7) - Denial of Service EDB-41350 · dos · Feb 12, 2017

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 1

WID-SEC-2026-3895 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 13, 2026

The TCP stack in the Linux kernel 3.x does not properly implement a SYN cookie protection mechanism for the case of a fast network connecti…