Cisco fixes TCP denial-of-service bug

Cisco fixes TCP denial-of-service bug

Cisco this week issued a patch for a denial-of-service vulnerability that affects multiple products.

The vulnerability allows attackers to manipulate the state of TCP connections, according to a Cisco security advisory released this week. By manipulating the state of a TCP connection, an attacker could force the TCP connection to remain in a long-lived state, possibly indefinitely, the Cisco advisory states.

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If enough TCP connections are forced into a long-lived or indefinite state, system resources may be consumed, preventing new TCP connections from being accepted and thus initiating a DoS condition. To exploit these vulnerabilities, an attacker must be able to complete a TCP three-way handshake with a vulnerable system, the advisory states.

The bug was first discovered a year ago by Outpost24, a Swedish provider of network security products.

Affected products include scores of routers and switches running IOS, IOS-XE and CatOS operating systems; Cisco ASA and Cisco PIX security appliances running versions 7.0, 7.1, 7.2, 8.0, and 8.1 under certain configurations; NX-OS-based products such as the new Nexus 5000 and 7000 swsitches; and Scientific-Atlanta and Linksys products.

In addition to these vulnerabilities, Nexus 5000 switches contain a TCP DoS vulnerability that may result in a system crash, the Cisco advisory states. This vulnerability can be exploited remotely without authentication and without user interaction, and repeated attempts to exploit this vulnerability could result in a sustained DoS condition.

Cisco says it has released free software updates for download from its Web site that address these vulnerabilities. Workarounds that mitigate these vulnerabilities are also available, the company says.

Cisco declined further comment on the situation.

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Sizing up the NZ security spectrum - Where's the channel sweet spot?

Sizing up the NZ security spectrum - Where's the channel sweet spot?

From new extortion schemes, outside threats and rising cyber attacks, the art of securing the enterprise has seldom been so complex or challenging. With distance no longer a viable defence, Kiwi businesses are fighting to stay ahead of the security curve. In total, 28 per cent of local businesses faced a cyber attack last year, with the number in New Zealand set to rise in 2017. Yet amidst the sensationalism, media headlines and ongoing high profile breaches, confusion floods the channel, as partners seek strategic methods to combat rising sophistication from attackers. In sizing up the security spectrum, this Reseller News roundtable - in association with F5 Networks, Kaspersky Lab, Tech Data, Sophos and SonicWall - assessed where the channel sweet spot is within the New Zealand channel. Photos by Maria Stefina.

Sizing up the NZ security spectrum - Where's the channel sweet spot?
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