Cisco IOS Data-Link Switching Memory leakage Remote Denial of Service Vulnerability

Release date:
Updated on:

Affected Systems:
Cisco IOS 15.x
Cisco IOS 12.x
Unaffected system:
Cisco IOS 15.1 (3) T
Cisco IOS 15.1 (2) T2a
Cisco IOS 15.1 (2) T2
Cisco IOS 15.1 (2) S
Cisco IOS 15.1 (1) T3
Cisco IOS 15.1 (1) S1
Cisco IOS 15.0 (1) S4
Cisco IOS 15.0 (1) S3a
Cisco IOS 15.0 (1) M5a
Cisco IOS 15.0 (1) M4
Cisco IOS 12.4 (25e)
Cisco IOS 12.4 (24) T5
Cisco IOS 12.4 (24) GC4
Cisco IOS 12.4 (2) XB12
Cisco IOS 12.4 (15) XM3
Cisco IOS 12.4 (15) XM
Cisco IOS 12.4 (15) T15
Cisco IOS 12.3 (2) XA7
Cisco IOS 12.3 (2) JK3
Cisco IOS 12.2 (8) YJ1
Cisco IOS 12.2 (50) SY
Cisco IOS 12.2 (40) SG
Cisco IOS 12.2 (4) YA8
Cisco IOS 12.2 (33) SXI6
Cisco IOS 12.2 (33) SXH8a
Cisco IOS 12.2 (33) SRE3
Cisco IOS 12.2 (33) SRD6
Cisco IOS 12.2 (33) SCE1
Cisco IOS 12.2 (33) stc7
Cisco IOS 12.2 (33) SCD6
Cisco IOS 12.2 (33) SCC7
Cisco IOS 12.2 (33) SB10
Cisco IOS 12.2 (33) IRE3
Cisco IOS 12.2 (33) IRD1
Cisco IOS 12.2 (31) SB20
Cisco IOS 12.2 (30) S
Cisco IOS 12.2 (29a) SV
Cisco IOS 12.2 (25) SW12
Cisco IOS 12.2 (2) B7
Cisco IOS 12.2 (18) SXF17b
Cisco IOS 12.2 (15) BX
Cisco IOS 12.2 (13) ZH6
Cisco IOS 12.2 (11) YV1
Description:
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Bugtraq id: 49829
Cve id: CVE-2011-0945

Cisco's Internet Operating System (IOS) is a complex operating system optimized for Internet interconnection. The data stream interaction function (DLSw) enables the transmission of ibm sna and network BIOS traffic over an IP network.

The DLSw feature has a memory leakage vulnerability in the implementation of Cisco IOS. Remote attackers can exploit this vulnerability to cause DoS attacks.

The Cisco IOS device configures the DLSw to listen to 91 packets of the IP protocol. According to the DLSw configuration, UDP port 2067 and multiple TCP ports can be opened. This vulnerability is exploited through ipprotocol 91 instead of UDP or TCP transmission.

<* Source: Cisco

Link: http://www.cisco.com/en/US/products/products_security_advisory09186a0080b95d59.shtml
*>

Suggestion:
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Vendor patch:

Cisco
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Cisco has released a Security Bulletin (cisco-sa-20110928-dlsw) and patches for this:

Cisco IOS Software Data-Link Switching Vulnerability

Link: http://www.cisco.com/warp/public/707/cisco-sa-20110928-dlsw.shtml