Menu
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.

Review: ASR 1000 ready to replace aging Cisco routers

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.


Follow Us

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Featured

Slideshows

Meet the leading female front runners of the Kiwi channel

Meet the leading female front runners of the Kiwi channel

Reseller News honoured the leading female front runners of the New Zealand channel at the 2018 Women in ICT Awards (WIICTA) in Auckland. The awards honoured standout individuals across seven categories, spanning Entrepreneur; Innovation; Rising Star; Shining Star; Community; Technical and Achievement.

Meet the leading female front runners of the Kiwi channel
Meet the top performing customer-centric Microsoft channel partners

Meet the top performing customer-centric Microsoft channel partners

Microsoft honoured leading partners across the channel following a year of customer innovation and market growth in New Zealand. The 2018 Microsoft Partner Awards recognised excellence within the context of the end-user, spanning a host of emerging and established providers.

Meet the top performing customer-centric Microsoft channel partners
Reseller News launches new-look Awards at 2018 Judges’ Lunch

Reseller News launches new-look Awards at 2018 Judges’ Lunch

Introducing the Reseller News Innovation Awards, launched to the channel at the 2018 Judges’ Lunch in Auckland. With more than 70 judges now part of the voting panel, the new-look awards will reflect the changing dynamics of the channel, recognising excellence across customer value and innovation - spanning start-ups, partners, distributors and vendors.

Reseller News launches new-look Awards at 2018 Judges’ Lunch
Show Comments