Attacks/Breaches
12/30/2013
08:17 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

Attackers Wage Network Time Protocol-Based DDoS Attacks

Yet another protocol being abused for flooding targets with unwanted traffic

Attackers have begun exploiting an oft-forgotten network protocol in a new spin on distributed denial-of-service (DDoS) attacks, as researchers spotted a spike in so-called NTP reflection attacks this month.

The Network Time Protocol, or NTP, syncs time between machines on the network, and runs over port 123 UDP. It's typically configured once by network administrators and often is not updated, according to Symantec, which discovered a major jump in attacks via the protocol over the past few weeks.

"NTP is one of those set-it-and-forget-it protocols that is configured once, and most network administrators don't worry about it after that. Unfortunately, that means it is also not a service that is upgraded often, leaving it vulnerable to these reflection attacks," says Allan Liska, a Symantec researcher in blog post last week.

Attackers appear to be employing NTP for DDoSing similar to the way DNS is being abused in such attacks. They transmit small spoofed packets requesting a large amount of data sent to the DDoS target's IP address. According to Symantec, it's all about abusing the so-called "monlist" command in an older version of NTP. Monlist returns a list of the last 600 hosts that have connected to the server. "For attackers the monlist query is a great reconnaissance tool. For a localized NTP server it can help to build a network profile. However, as a DDoS tool, it is even better because a small query can redirect megabytes worth of traffic," Liska explains in the post.

Monlist modules can be found in NMAP as well as in Metasploit, for example. Metasploit includes monlist DDoS exploit module.

The spike in NTP reflection attacks occurred mainly in mid-December, with close to 15,000 IPs affected, and dropped off significantly after Dec. 23, according to Symantec's data.

Symantec recommends that organizations update their NTP implementations to version 4.2.7, which does not use the monlist command. Another option is to disable access to monlist in older versions of NTP. "By disabling monlist, or upgrading so the command is no longer there, not only are you protecting your network from unwanted reconnaissance, but you are also protecting your network from inadvertently being used in a DDoS attack," Liska says.

Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.

Kelly Jackson Higgins is Executive Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
JohnB831
50%
50%
JohnB831,
User Rank: Apprentice
1/6/2014 | 4:01:19 PM
re: Attackers Wage Network Time Protocol-Based DDoS Attacks
modify /etc/ntp.conf to have the line:

disable monitor
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Dark Reading December Tech Digest
Experts weigh in on the pros and cons of end-user security training.
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-4807
Published: 2014-11-22
Sterling Order Management in IBM Sterling Selling and Fulfillment Suite 9.3.0 before FP8 allows remote authenticated users to cause a denial of service (CPU consumption) via a '\0' character.

CVE-2014-6183
Published: 2014-11-22
IBM Security Network Protection 5.1 before 5.1.0.0 FP13, 5.1.1 before 5.1.1.0 FP8, 5.1.2 before 5.1.2.0 FP9, 5.1.2.1 before FP5, 5.2 before 5.2.0.0 FP5, and 5.3 before 5.3.0.0 FP1 on XGS devices allows remote authenticated users to execute arbitrary commands via unspecified vectors.

CVE-2014-8626
Published: 2014-11-22
Stack-based buffer overflow in the date_from_ISO8601 function in ext/xmlrpc/libxmlrpc/xmlrpc.c in PHP before 5.2.7 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code by including a timezone field in a date, leading to improper XML-RPC encoding...

CVE-2014-8710
Published: 2014-11-22
The decompress_sigcomp_message function in epan/sigcomp-udvm.c in the SigComp UDVM dissector in Wireshark 1.10.x before 1.10.11 allows remote attackers to cause a denial of service (buffer over-read and application crash) via a crafted packet.

CVE-2014-8711
Published: 2014-11-22
Multiple integer overflows in epan/dissectors/packet-amqp.c in the AMQP dissector in Wireshark 1.10.x before 1.10.11 and 1.12.x before 1.12.2 allow remote attackers to cause a denial of service (application crash) via a crafted amqp_0_10 PDU in a packet.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
Now that the holiday season is about to begin both online and in stores, will this be yet another season of nonstop gifting to cybercriminals?