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Security Advisory

CommScope Ruckus IoT Controller Undocumented Account

Advisory ID
KL-001-2021-007
CVE ID
CVE-2021-33216
Published
2021-05-26
Vendor
CommScope

Affected Systems

Product
Ruckus IoT Controller
Version
1.7.1.0 and earlier
Platform
Linux

Discovered By

Jim Becher (KoreLogic)
Download (signed .txt)
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Vulnerability Details

Affected Vendor: CommScope
Affected Product: Ruckus IoT Controller
Affected Version: 1.7.1.0 and earlier
Platform: Linux
CWE Classification: CWE-798: Use of Hard-coded Credentials, CWE-912: Hidden Functionality
CVE ID: CVE-2021-33216

Vulnerability Description

An upgrade account is included in the IoT Controller OVA that provides the vendor undocumented access via Secure Copy (SCP).

Technical Description

Once the OVA is imported into VirtualBox, a VMDK file is created. The VMDK file can be mounted and the directory structure and its contents can be perused.

An authorized_keys file exists that allows an individual/organization possessing the SSH private key to access the virtual appliance using the vriotiotupgrade account. The vriotiotupgrade account is restricted to scp, per the rssh configuration.

Additionally, it appears that the IoT Controller has rssh version 2.3.4 installed and in use. At the time of this advisory, there are at least three remote command injection vulnerabilities in this particular version of rssh: CVE-2019-3463, CVE-2019-3464 and CVE-2019-1000018.

Mitigation and Remediation Recommendation

The vendor has released an updated firmware (1.8.0.0) which remediates the described vulnerability. Firmware and release notes are available at:

https://www.commscope.com/globalassets/digizuite/917216-faq-security-advisory-id-20210525-v1-0.pdf

Credit

This vulnerability was discovered by Jim Becher (@jimbecher) of KoreLogic, Inc.

Proof of Concept

With the VMDK file mounted at the current working directory:

$ find . -name authorized_keys
./VRIOT/ap-images/authorized_keys
./VRIOT/ops/ap-images/authorized_keys

$ cat VRIOT/ap-images/authorized_keys
ssh-rsa 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 chandini.venkatesh@commscope.com

$ cat VRIOT/ops/ap-images/authorized_keys
ssh-rsa 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 chandini.venkatesh@commscope.com

$ grep "ap-images" etc/passwd
vriotiotupgrade:x:1002:1002::/VRIOT/ap-images/:/usr/bin/rssh

$ tail -8 etc/ssh/sshd_config
Match User vriotiotupgrade
    PasswordAuthentication no
    AuthorizedKeysFile     /VRIOT/ap-images/authorized_keys

Match User vriotha
PasswordAuthentication yes

$ grep -v ^# etc/rssh.conf
logfacility = LOG_USER
allowscp
umask = 022

The contents of this advisory are copyright(c) 2021 KoreLogic, Inc. and are licensed under a Creative Commons Attribution Share-Alike 4.0 (United States) License: http://creativecommons.org/licenses/by-sa/4.0/

KoreLogic, Inc. is a founder-owned and operated company with a proven track record of providing security services to entities ranging from Fortune 500 to small and mid-sized companies. We are a highly skilled team of senior security consultants doing by-hand security assessments for the most important networks in the U.S. and around the world. We are also developers of various tools and resources aimed at helping the security community. https://www.korelogic.com/about-korelogic.html

Our public vulnerability disclosure policy is available at: https://korelogic.com/KoreLogic-Public-Vulnerability-Disclosure-Policy.v2.3.txt

Disclosure Timeline

KoreLogic submits vulnerability details to CommScope.

CommScope acknowledges receipt and the intention to investigate.

CommScope notifies KoreLogic that this issue, along with several others reported by KoreLogic, will require more than the standard 45 business day remediation timeline.

KoreLogic agrees to extend disclosure embargo if necessary.

CommScope informs KoreLogic that remediation for this vulnerability will be available inside of the standard 45 business day timeline. Requests KoreLogic acquire CVE number for this vulnerability.

30 business days have elapsed since the vulnerability was reported to CommScope.

CommScope notifies KoreLogic that the patched version of the firmware will be available the week of 2021.05.24.

KoreLogic requests CVE from MITRE.

MITRE issues CVE-2021-33216.

CommScope releases firmware 1.8.0.0 and associated advisory.

KoreLogic public disclosure.

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Responsible Disclosure

KoreLogic follows responsible disclosure practices. All vulnerabilities are reported to affected vendors with appropriate time for remediation before public disclosure.

Vendor notification and coordination
90+ day disclosure timeline
CVE coordination when applicable

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