Cisco small business phones open to remote eavesdropping, calling

An authentication flaw allows attackers to listed to audio streams and make calls from Cisco SPA 300 and 500 IP phones

You don't need to be the NSA to tap calls on Cisco's SPA 300 and 500 IP phones: An authentication flaw allows potential attackers to do that by default.

An unpatched vulnerability in the firmware of the SPA 300 and 500 series IP phones, typically used by small businesses, could allow eavesdropping on calls.

"The vulnerability is due to improper authentication settings in the default configuration," Cisco Systems said in a security advisory.

Unauthenticated remote attackers could send crafted XML requests to affected devices in order to exploit the flaw and remotely listen to audio streams or make phone calls through them, the company warned.

Cisco determined that phones running version 7.5.5 of the firmware are vulnerable, but said that later versions may also be affected. No patches are currently available, so phone owners are advised to take other safeguards.

Administrators should enable XML Execution authentication in the configuration settings of the affected devices and should make sure that only trusted users have access to the networks where the phones are installed, the company said. Solid firewall strategies and IP-based access control lists can also be used to protect the affected systems from external attacks.

According to Cisco, the fact that these systems are typically installed on internal networks, behind firewalls, may reduce the likelihood of a successful exploit, as attackers would first need to gain access to those networks.

However, it's likely that some phones have been configured to be accessible from the Internet and it would be fairly easy for attackers to locate them, for example by using the specialized device search engine SHODAN.

Join the CSO newsletter!

Error: Please check your email address.

Tags Cisco SystemsintrusionsecurityAccess control and authenticationExploits / vulnerabilities

More about CiscoNSA

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Lucian Constantin

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts

Market Place