Dropbear authorized_keys File Format Unauthorized File Read Vulnerability [CVE-2017-9079]
CVE Number – CVE-2017-9079
A vulnerability in Dropbear could allow a local attacker to access sensitive information on a targeted system.
The vulnerability is due to improper parsing of the authorized_keys file as root by the affected software, even if the file is a symbolic link (symlink). An attacker could exploit this vulnerability by creating a symlink of their /.ssh/authorized_keys file to a valid authorized_keys formatted file owned by root with command= options. A successful exploit could allow the attacker to read other sensitive contents of that file, which could be used to conduct further attacks.
The vendor confirmed the vulnerability and released software updates.
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To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.
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Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to access local systems.
Administrators are advised to allow only privileged users to access administration or management systems.
Administrators are advised to monitor critical systems.
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The vendor released a changelog at the following link: 2017.75 – 18 May 2017
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The vendor released software updates at the following link: Dropbear 2017.75 or later
Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.