RFC Errata


Errata Search

 
Source of RFC  
Summary Table Full Records

RFC 8270, "Increase the Secure Shell Minimum Recommended Diffie-Hellman Modulus Size to 2048 Bits", December 2017

Source of RFC: curdle (sec)

Errata ID: 5502
Status: Reported
Type: Editorial
Publication Format(s) : TEXT

Reported By: Eugene Adell
Date Reported: 2018-09-21

Section 5 says:

   A malicious client could cause a Denial of Service by intentionally
   making multiple connections that are less than 2048 bits in size.
   Therefore, operating systems SHOULD NOT log DH groups that are less
   than 2048 bits in size, as it would create an additional attack
   surface.

It should say:

   A malicious client could cause a Denial of Service by intentionally
   making multiple connections that are less than 2048 bits in size.
   Therefore, operating systems without any rate-limited logging 
   SHOULD NOT log DH groups that are less than 2048 bits in size, as it
   would create an additional attack surface.

Notes:

Instead of ignoring attacks, the administrator wants to know when one is taking place, particularly if it is an intense one which would lead to a denial of service, as suggested by the authors. Thus, using a rate-limited logging mechanism is an appropriate solution to keep records of the attack, and to notify the administrator in real-time then he can take actions if he wants to. As there might not be other ways to inform the administrator of an attack taking place, not logging at all is the last choice.

Report New Errata