TCP/IP SYN+FIN Packet Filtering Weakness

Medium Nessus Plugin ID 11618


It may be possible to bypass firewall rules.


The remote host does not discard TCP SYN packets that have the FIN flag set.

Depending on the kind of firewall you are using, an attacker may use this flaw to bypass its rules.


Contact your vendor for a patch.

See Also

Plugin Details

Severity: Medium

ID: 11618

File Name: tcpip_ambiguities.nasl

Version: $Revision: 1.26 $

Type: remote

Family: Firewalls

Published: 2003/05/12

Modified: 2016/11/03

Risk Information

Risk Factor: Medium


Base Score: 5

Temporal Score: 4.3

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Temporal Vector: CVSS2#E:H/RL:OF/RC:C

Vulnerability Information

Required KB Items: Settings/ParanoidReport

Exploit Available: true

Exploit Ease: No exploit is required

Vulnerability Publication Date: 2002/10/18

Reference Information

BID: 7487

OSVDB: 2118

CERT: 464113