xrdp is an open source RDP server. xrdp versions prior to 0.10.0 have a vulnerability that allows attackers to make an infinite number of login attempts. The number of max login attempts is supposed to be limited by a configuration parameter MaxLoginRetry
in /etc/xrdp/sesman.ini
. However, this mechanism was not effectively working. As a result, xrdp allows an infinite number of login attempts.
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame, making it more susceptible to brute force attacks.
Common protection mechanisms include:
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]