ppp is a Unix implementation of the Point-to-Point Protocol.
The pppd server improperly verifies header fields, potentially leading to a crash of the pppd process handling the connection. However, since a separate pppd process handles each ppp connection, this would not affect any other connection, or prevent new connections from being established.
We incorrectly thought that this bug could be exploited to deny service to all ppp users. It is not the case, this bug has no security impact whatsoever. Many thanks to Paul Mackerras from the Samba team for correcting our mistake.
There is no need for a workaround.
ppp users can keep their current versions.