Affected Systems
Discovered By
Vulnerability Details
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 = 022The 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.
Responsible Disclosure
KoreLogic follows responsible disclosure practices. All vulnerabilities are reported to affected vendors with appropriate time for remediation before public disclosure.