title: SACK can cause extensive memory use via fragmented resend queue
description: 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.
problem types: CWE-770 Allocation of Resources Without Limits or Throttling
affected:
{
product: Linux kernel
vendor: Linux
versions:
lessThan: 4.4.182, status: affected, version: 4.4, versionType: custom
lessThan: 4.9.182, status: affected, version: 4.9, versionType: custom
lessThan: 4.14.127, status: affected, version: 4.14, versionType: custom
lessThan: 4.19.52, status: affected, version: 4.19, versionType: custom
lessThan: 5.1.11, status: affected, version: 5.1, versionType: custom
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 5.3
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
version: 3.0
]