IBM OS/400 TCP SYN packets security bypass

os400-tcpsyn-security-bypass (35173)

Medium Risk

Description:

IBM OS/400 could allow a remote attacker to bypass security restrictions, caused by an error when TCP SYN packets with the FIN flag set are not discarded. A remote attacker could exploit this vulnerability to bypass firewall rules and gain unauthorized access to the system.

*CVSS:

Base Score:	7
Access Vector:	Remote
Access Complexity:	Low
Authentication:	Not Required
Confidentiality Impact:	Partial
Integrity Impact:	Partial
Availability Impact:	Partial
Temporal Score:	5.2
Exploitability:	Unproven
Remediation Level:	Official-Fix
Report Confidence:	Confirmed

Consequences:

Gain Privileges

Remedy:

Refer to IBM APAR MA28921 for patch, upgrade, or suggested workaround information. See References.

References:

• IBM APAR MA28921 : LIC-COMM-TCPIP PACKET WITH SYN AND FIN FLAG NOT DISCARDED.
• BID-24706: IBM OS/400 TCP Packet Security Bypass Weakness
• CVE-2007-3537: IBM OS/400 (aka i5/OS) V4R2M0 through V5R3M0 on iSeries machines sends responses to TCP SYN-FIN packets, which allows remote attackers to obtain system information and possibly bypass firewall rules.
• SA25885: IBM OS/400 TCP Packet Processing Security Bypass Issue

Platforms Affected:

• IBM i5OS
• IBM OS 400 V4R2M0
• IBM OS 400 V4R3M0
• IBM OS 400 V4R4M0
• IBM OS 400 V4R5M0
• IBM OS 400 V5R1M0
• IBM OS 400 V5R2M0
• IBM OS 400 V5R3M0

Reported:

Jun 29, 2007

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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