Critical Vulnerabilities in Dropbear SSH version on Deco
Nessus Security Scanner complains about the version of Dropbear SSH on the Deco M5s I have installed. Apparently there are several critical exploits that allow for remote code execution. I get that from the WAN iptables will block access to SSH, but, that doesn't rule out lateral attacks from the LAN. Does TP-Link have any plans to upgrade to a version of Dropbear that is not vulnerable?
Here are the results of the scan:
Description
According to its self-reported version in its banner, Dropbear SSH running on the remote host is prior to 2016.74. It is, therefore, affected by the following vulnerabilities :
- A format string flaw exists due to improper handling of string format specifiers (e.g., %s and %x) in usernames and host arguments. An unauthenticated, remote attacker can exploit this to execute arbitrary code with root privileges. (CVE-2016-7406)
- A flaw exists in dropbearconvert due to improper handling of specially crafted OpenSSH key files. An unauthenticated, remote attacker can exploit this to execute arbitrary code. (CVE-2016-7407)
- A flaw exists in dbclient when handling the -m or -c arguments in scripts. An unauthenticated, remote attacker can exploit this, via a specially crafted script, to execute arbitrary code. (CVE-2016-7408)
- A flaw exists in dbclient or dropbear server if they are compiled with the DEBUG_TRACE option and then run using the -v switch. A local attacker can exploit this to disclose process memory. (CVE-2016-7409)
Solution
Upgrade to Dropbear SSH version 2016.74 or later.
Output
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Version source : SSH-2.0-dropbear_2015.67 Installed version : 2015.67 Fixed version : 2016.74