Vulnerabilities / Threats

9/20/2017
05:55 PM
Connect Directly
Twitter
LinkedIn
Google+
RSS
E-Mail
50%
50%

Cisco SMI Still Exposing Network Switches Online

The high number of exposed and vulnerable devices online has remained largely unchanged since researchers began exploring SMI in 2010.

Cisco's Smart Install (SMI) protocol is leaving network switches exposed on the public Internet at a rate that has remained largely unchanged since researchers began digging for SMI flaws when it was first released in 2010, a new study shows.

SMI provides configuration and image management for Cisco switches and uses a combination of DHCP, TFTP, and a proprietary TCP protocol to help businesses deploy and run them.

Researchers at Rapid7 recently reassessed the public Internet for SMI exposure. Their goal was to highlight changes since the initial publication of SMI research and learn more about why SMI was being exposed insecurely.

Since its debut, several SMI flaws have been discovered and disclosed including CVE-2011-3271, which led to remote code execution, and denial of service issues CVE-2012-0385, CVE-2013-1146, CVE-2016-1349, and CVE-2016-6385.

In 2016, researchers have found a number of new SMI security issues. Experts from Tenable, Trustwave SpiderLabs, and Digital Security presented at the 2016 Zeronights security conference to disclose several problems with SMI that left the entire switch open for compromise if a user left SMI exposed and unpatched, neglecting Cisco's recommendations for securing it.

Each SMI-related security advisory published by Cisco has recommended disabling SMI unless it's needed. The company has offered coverage for SMI abuse, updated the documentation to secure SMI, and released a scanning tool so customers can know if they're affected by SMI problems. It also released SMI-related hardening fixes.

In its new July 2017 reassessment of the public Internet, Rapid7 used a method similar to Zeronights. The Rapid7 Labs' Sonar scan found a 13% decrease in the number of exposed SMI endpoints compared with the Zeronights research. Countries with a large number of IPv4 IPs and large network infrastructure are the most exposed. The United States was highest with 56,605 nodes exposed, or 26.3% of the total.

"The issue with exposing SMI is that it gives an attacker complete control over the configuration of the target switch," says Jon Hart, senior security researcher at Rapid7. At the minimum, he explains, there is the possibility of information disclosure, which is likely to include authentication data like usernames, passwords/hashes, firewall/ACL rules, and more.

On the more extreme end, he continues, SMI exposure could let an attacker completely compromise the target switch and load arbitrary switch operating system code. They could execute code of their choosing and modify, redirect, or intercept switch transit traffic.

"Compromising a switch puts an attacker in a very advantageous position offensively," says Hart. "Being closer network-wise to additional target devices that connect to or through the compromised switch affords an attacker the ability to perform attacks against these additional targets."

Businesses can protect themselves by updating to newer versions of the relevant code powering these switches, which will likely remove any current risk of being compromised via SMI, he says. It's an improvement from several years ago, when organizations could have been running and exposing SMI without knowing it.

Related Content:

Join Dark Reading LIVE for two days of practical cyber defense discussions. Learn from the industry’s most knowledgeable IT security experts. Check out the INsecurity agenda here.

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Russia Hacked Clinton's Computers Five Hours After Trump's Call
Robert Lemos, Technology Journalist/Data Researcher,  4/19/2019
Tips for the Aftermath of a Cyberattack
Kelly Sheridan, Staff Editor, Dark Reading,  4/17/2019
Why We Need a 'Cleaner Internet'
Darren Anstee, Chief Technology Officer at Arbor Networks,  4/19/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
5 Emerging Cyber Threats to Watch for in 2019
Online attackers are constantly developing new, innovative ways to break into the enterprise. This Dark Reading Tech Digest gives an in-depth look at five emerging attack trends and exploits your security team should look out for, along with helpful recommendations on how you can prevent your organization from falling victim.
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-11498
PUBLISHED: 2019-04-24
WavpackSetConfiguration64 in pack_utils.c in libwavpack.a in WavPack through 5.1.0 has a "Conditional jump or move depends on uninitialised value" condition, which might allow attackers to cause a denial of service (application crash) via a DFF file that lacks valid sample-rate data.
CVE-2019-11490
PUBLISHED: 2019-04-24
An issue was discovered in Npcap 0.992. Sending a malformed .pcap file with the loopback adapter using either pcap_sendqueue_queue() or pcap_sendqueue_transmit() results in kernel pool corruption. This could lead to arbitrary code executing inside the Windows kernel and allow escalation of privilege...
CVE-2019-11486
PUBLISHED: 2019-04-23
The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel before 5.0.8 has multiple race conditions.
CVE-2019-11487
PUBLISHED: 2019-04-23
The Linux kernel before 5.1-rc5 allows page->_refcount reference count overflow, with resultant use-after-free issues, if about 140 GiB of RAM exists. This is related to fs/fuse/dev.c, fs/pipe.c, fs/splice.c, include/linux/mm.h, include/linux/pipe_fs_i.h, kernel/trace/trace.c, mm/gup.c, and mm/hu...
CVE-2018-7576
PUBLISHED: 2019-04-23
Google TensorFlow 1.6.x and earlier is affected by: Null Pointer Dereference. The type of exploitation is: context-dependent.