Severity Medium
Remote Yes
Type Arbitrary code execution
The bounds check in the read_key() function in OpenVPN before 2.4.4 and 2.3.18 was performed after using the value, instead of before.  If 'key-method 1' is used, this allowed an attacker to send a malformed packet to trigger a stack buffer overflow.
Note that 'key-method 1' has been replaced by 'key method 2' as the default in OpenVPN 2.0 (released on 2005-04-17), and explicitly deprecated in 2.4 and marked for removal in 2.5. This should limit the amount of users impacted by this issue.
Group Package Affected Fixed Severity Status Ticket
AVG-420 openvpn 2.4.3-3 2.4.4-1 Medium Fixed
Date Advisory Group Package Severity Description
28 Sep 2017 ASA-201709-21 AVG-420 openvpn Medium arbitrary code execution