CVE-2019-11478

Published: 17 June 2019

Jonathan Looney discovered that the TCP retransmission queue implementation in tcp_fragment in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commit f070ef2ac66716357066b683fb0baf55f8191a2e.

From the Ubuntu Security Team

Jonathan Looney discovered that the TCP retransmission queue implementation in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. A remote attacker could use this to cause a denial of service.

Notes

Author	Note
tyhicks	This vulnerability results in exhausted CPU resources on kernels < 4.15 This vulnerability results in exhausted kernel memory on kernels >= 4.15

Priority

Cvss 3 Severity Score

7.5

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-52.56)
	cosmic	Released (4.18.0-22.23)
	disco	Released (5.0.0-17.18)
	trusty	Released (3.13.0-171.222) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.2~rc6)
	xenial	Released (4.4.0-151.178)
	Patches: Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Fixed by f070ef2ac66716357066b683fb0baf55f8191a2e
linux-aws Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1041.43)
	cosmic	Released (4.18.0-1018.20)
	disco	Released (5.0.0-1008.8)
	trusty	Released (4.4.0-1046.50) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.2~rc6)
	xenial	Released (4.4.0-1085.96)
linux-aws-hwe Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-1041.43~16.04.1)
linux-azure Launchpad, Ubuntu, Debian	bionic	Released (4.18.0-1020.20~18.04.1)
	cosmic	Released (4.18.0-1020.20)
	disco	Released (5.0.0-1008.8)
	trusty	Released (4.15.0-1047.51~14.04.1) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-1047.51)
linux-azure-edge Launchpad, Ubuntu, Debian	bionic	Released (4.18.0-1020.20~18.04.1)
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-1047.51)
linux-euclid Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Ignored (end of life, was needed)
linux-flo Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Ignored (abandoned)
linux-gcp Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1034.36)
	cosmic	Released (4.18.0-1013.14)
	disco	Released (5.0.0-1008.8)
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-1034.36~16.04.1)
linux-gcp-edge Launchpad, Ubuntu, Debian	bionic	Released (4.18.0-1013.14~18.04.1)
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-gke Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Ignored (end of standard support)
linux-gke-4.15 Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1034.36)
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-gke-5.0 Launchpad, Ubuntu, Debian	bionic	Not vulnerable (5.0.0-1011.11~18.04.1)
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-goldfish Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Ignored (end of life)
linux-grouper Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-hwe Launchpad, Ubuntu, Debian	bionic	Released (4.18.0-22.23~18.04.1)
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-52.56~16.04.1)
linux-hwe-edge Launchpad, Ubuntu, Debian	bionic	Released (5.0.0-17.18~18.04.1)
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-52.56~16.04.1)
linux-kvm Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1036.36)
	cosmic	Released (4.18.0-1014.14)
	disco	Released (5.0.0-1008.8)
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.4.0-1048.55)
linux-lts-trusty Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-lts-utopic Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-lts-vivid Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-lts-wily Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-lts-xenial Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Released (4.4.0-151.178~14.04.1) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-maguro Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-mako Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Ignored (abandoned)
linux-manta Launchpad, Ubuntu, Debian	bionic	Does not exist
	cosmic	Does not exist
	disco	Does not exist
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Does not exist
linux-oem Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1043.48)
	cosmic	Released (4.15.0-1043.48)
	disco	Released (4.15.0-1043.48)
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Ignored (end of standard support, was needed)
linux-oracle Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1015.17)
	cosmic	Released (4.15.0-1015.17)
	disco	Released (4.15.0-1015.17)
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.15.0-1015.17~16.04.1)
linux-raspi2 Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1038.40)
	cosmic	Released (4.18.0-1016.18)
	disco	Released (5.0.0-1010.10)
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.4.0-1111.120)
linux-snapdragon Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1055.59)
	cosmic	Does not exist
	disco	Released (5.0.0-1014.14)
	trusty	Does not exist
	upstream	Released (5.2~rc6)
	xenial	Released (4.4.0-1115.121)

Severity score breakdown

Parameter	Value
Base score	7.5
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Bugs

https://launchpad.net/bugs/1831638

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