TCP/IP Predictable ISN (Initial Sequence Number) Generation Weakness

high Nessus Plugin ID 10443
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It is possible to predict TCP/IP Initial Sequence Numbers for the remote host.


The remote host has predictable TCP sequence numbers.

An attacker may use this flaw to establish spoofed TCP connections to this host.


Contact your vendor for a patch.

Plugin Details

Severity: High

ID: 10443

File Name: tcp_seq.nasl

Version: 1.31

Type: remote

Family: General

Published: 3/3/2003

Updated: 3/6/2019

Configuration: Enable paranoid mode

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

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

Vulnerability Information

Required KB Items: Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 1/1/1995

Reference Information

CVE: CVE-1999-0077, CVE-2004-0641, CVE-2001-0162, CVE-2001-0163, CVE-2001-0751, CVE-2001-0288, CVE-2001-1104, CVE-2000-0916

BID: 107, 670, 3098, 10881