Linux Kernel TCP Sequence Number Generation Security Weakness

medium Nessus Plugin ID 56283
New! Vulnerability Priority Rating (VPR)

Tenable calculates a dynamic VPR for every vulnerability. VPR combines vulnerability information with threat intelligence and machine learning algorithms to predict which vulnerabilities are most likely to be exploited in attacks. Read more about what VPR is and how it is different from CVSS.

VPR Score: 5.2

Synopsis

It may be possible to predict TCP/IP Initial Sequence Numbers for the remote host.

Description

The Linux kernel is prone to a security weakness related to TCP sequence number generation. Attackers can exploit this issue to inject arbitrary packets into TCP sessions using a brute-force attack.

An attacker may use this vulnerability to create a denial of service condition or a man-in-the-middle attack.

Note that this plugin may fire as a result of a network device (such as a load balancer, VPN, IPS, transparent proxy, etc.) that is vulnerable and that re-writes TCP sequence numbers, rather than the host itself being vulnerable.

Solution

Contact the OS vendor for a Linux kernel update / patch.

See Also

https://lwn.net/Articles/455135/

http://www.nessus.org/u?62a845fa

Plugin Details

Severity: Medium

ID: 56283

File Name: linux_isn.nasl

Version: 1.17

Type: remote

Family: General

Published: 9/23/2011

Updated: 3/6/2019

Configuration: Enable paranoid mode

Risk Information

Risk Factor: Medium

VPR Score: 5.2

CVSS v2.0

Base Score: 6.8

Temporal Score: 5

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C

Vulnerability Information

Required KB Items: Settings/ParanoidReport

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 8/23/2011

Reference Information

CVE: CVE-2011-3188

BID: 49289