CVE-2019-11477

Public on 2019-06-13
Modified on 2019-06-17
Description
An integer overflow flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS).
Severity
Important
CVSS v3 Base Score
7.5
See breakdown

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 2 kernel 2019-06-13 22:11 ALAS2-2019-1222
Amazon Linux 1 kernel 2019-06-13 21:37 ALAS-2019-1222

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD CVSSv2 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C
NVD CVSSv3 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H