Saint SACK slowness

Technical record

Disclosed on

June 18 2019

CVE

CVE-2019-11478CVE-2019-5599

CVSS

5.3

Product

Linux · Linux kernel

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.

Sources: tenable.com