Juniper NetScreen firewall should be patched now

As experts predicted, the flawed code and exploits are already available

The Internet Storm Center has upgraded its warning about the corruption of Juniper ScreenOS firewalls to yellow, which means it’s imperative to patch them today, literally, given that details on how to exploit the flaws has been published and that it’s a holiday week when applying firewall patches can be easily overlooked.

According to the ISC warning, the upgraded yellow warning was made because Juniper’s NetScreen firewalls are popular and that the “'backdoor’ password is now known, and exploitation is trivial at this point,” and for most businesses, this “being a short week for many of us, addressing this issue today is critical.”

+ More on Network World: The weirdest, wackiest and coolest sci/tech stories of 2015 +

Juniper owned up last week to unauthorized code being present saying its ScreenOS enables two exploits. The first is a password – <<< %s(un='%s') = %u – see that works with any valid username. The second is a vulnerability in the version of the IPSec encryption code used by the machines that enables decrypting the VPN traffic.

Disabling the universal backdoor password is impossible without applying the patches, the ISC says. It’s easy to figure out if a machine needs the update: try out the universal password with a valid username. Or just compare the ScreenOS version on the macine with the list of vulnerable versions, ScreenOS 6.2.0r15 through 6.2.0r18 and 6.3.0r12 through 6.3.0r20.

+More on Network World: Juniper faces many questions after spying code planted in software+

Detecting whether anyone exploited the vulnerabilities on particular machines is more complicated and less sure, ISC says, because it calls for checking login logs, and the unauthorized entries look just like the legitimate ones.

The first suggestion is for checking telnet logins. It calls for following snort rules published by security consulting firm FoxIT, which detect telnet sessions that have been established with the devices. If there are such sessions, the rules then look for the telltale password.

A second flaw that allows SSH logins is also addressed, but differently because the password is encrypted. In that case the rules finds all the SSH logins and searches for “the typical NetScreen SSH banner,” ISC says.

Meanwhile, Juniper has remained silent about the problem since its initial disclosure last week, leaving unanswered some important questions.

Customers understandably want to know how the unauthorized code got into the operating system for a security device in the first place, shipping with every unit. And how did it go undetected for so long, at least two years by most accounts?

The implication is that VPN traffic customers was secure actually wasn’t because, at the very least, whoever sabotaged the IPSec encryption code could decrypt it. A second problem is that the devices could be used as a way in to infiltrate networks in hopes of stealing data or causing damage.

How the code got there is important because it will speak to the likely culprits and more accurate conclusions about their motives and possible intended targets. It will also speak to whether customers ought to be worried about possible flaws in other Juniper products.

Juniper’s silence can be interpreted in several ways.

It could be its legal team is telling it to say as little as possible in order to minimize the grounds for lawsuits against the company.

Juniper may be taking time briefing its biggest customers on the details under NDA in hopes they will issue public assurances that they are satisfied the devices, once patched, are trustworthy. Such endorsements could help ease the fears of smaller customers.

If placing the unauthorized code was the work of a government agency, say the NSA, the company could be under a Patriot Act gag. Since there are two instances of unauthorized code, the possibility exists that they were put there by separate parties.

Join the CSO newsletter!

Error: Please check your email address.

More about CustomersJuniperNetScreenNSASSH

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Tim Greene

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 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

More videos

Blog Posts

Market Place