Dropbear TCP Listeners Remote Code Execution Vulnerability [CVE-2017-9078]
CVE Number – CVE-2017-9078
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A vulnerability in Dropbear could allow an authenticated, remote attacker to execute arbitrary code on a targeted system.
The vulnerability exists because of a double-free memory condition that could occur during cleanup operations of TCP listeners by the affected software when the -a option is enabled. An attacker could exploit this vulnerability by sending a request that submits malicious input to the targeted system. A successful exploit could allow the attacker to execute arbitrary code with root privileges, which could result in a complete system compromise.
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.
Affected versions of Dropbear must have the -a option enabled for a successful exploit to occur.
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Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor affected 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.