Availability of Annual Report

Corero Network Security plc

("Corero" or the "Company")

Availability of Annual Report

Corero Network Security plc (AIM: CNS), the network security and business software provider, announces that, following the notification of its audited results for the year ended 31 December 2012 on 26 March 2013, its full annual report and accounts for that period are now available on its website, www.coreroplc.com/investors/results, in accordance with AIM Rule 20, and will be posted to shareholders on or around 5 April 2013.

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About Corero Network Security plc

Corero Network Security plc consists of two businesses: Corero Network Security and Corero Business Systems.

Corero Network Security is an international network security company and a leading provider of next generation securitysolutions. Deployed as a First Line of Defense solution, Corero's products and services sit outside a client's network, effectively stopping unwanted traffic (including Distributed Denial of Service ("DDoS") cyber-attacks)from reaching and overwhelming firewalls and other infrastructure components, such that good customer traffic can flow unimpeded.

Corero's First Line of Defense solution utilises sophisticated techniques and technologies to block malicious traffic to stop DDoS and other advanced cyber-attacks before they enter an organisation's IT infrastructure. This First Line of Defense solution helps customers worldwide, including enterprises, service providers and government organisations safeguard their IT infrastructure and eliminate downtime, ultimately protecting their bottom line.

Corero Business Systems is a leading provider of accounting, human resources, payroll and management information software to the schools (including academies) and further education and commercial sectors in the UK and internationally.

Corero's proprietary software solutions include:

• Resource Financials & HR - a finance and HR management solution delivering web-enabled and workflow controlled business processes.

• Resource EMS - a student record and learner management information solution for the post 16 education sector.

Corero Resource Financials & HR software won The UK Business Software Industry Software Satisfaction Awards 2012 in the category of Accounting & Finance (corporate).