chronyd.8.in | 2 1 + 1 - 0 !
1 file changed, 1 insertion(+), 1 deletion(-)

     fix small typo in manpage

Makefile.in | 6 3 + 3 - 0 !
1 file changed, 3 insertions(+), 3 deletions(-)

     recreate always getdate.c

configure | 4 2 + 2 - 0 !
1 file changed, 2 insertions(+), 2 deletions(-)

     do not look for ncurses

Makefile.in | 4 2 + 2 - 0 !
1 file changed, 2 insertions(+), 2 deletions(-)

     disable installation of license

ntp_core.c | 19 8 + 11 - 0 !
1 file changed, 8 insertions(+), 11 deletions(-)

 ntp: protect authenticated symmetric associations against dos attacks

An attacker knowing that NTP hosts A and B are peering with each other
(symmetric association) can send a packet with random timestamps to host
A with source address of B which will set the NTP state variables on A
to the values sent by the attacker. Host A will then send on its next
poll to B a packet with originate timestamp that doesn't match the
transmit timestamp of B and the packet will be dropped. If the attacker
does this periodically for both hosts, they won't be able to synchronize
to each other. It is a denial-of-service attack.

According to [1], NTP authentication is supposed to protect symmetric
associations against this attack, but in the NTPv3 (RFC 1305) and NTPv4
(RFC 5905) specifications the state variables are updated before the
authentication check is performed, which means the association is
vulnerable to the attack even when authentication is enabled.

To fix this problem, save the originate and local timestamps only when
the authentication check (test5) passed.

[1] https://www.eecis.udel.edu/~mills/onwire.html

addrfilt.c | 5 4 + 1 - 0 !
1 file changed, 4 insertions(+), 1 deletion(-)

 addrfilt: fix access configuration with subnet size indivisible by 4

When NTP or cmdmon access was configured (from chrony.conf or via
authenticated cmdmon) with a subnet size that is indivisible by 4 and
an address that has nonzero bits in the 4-bit subnet remainder (e.g.
192.168.15.0/22 or f000::/3), the new setting was written to an
incorrect location, possibly outside the allocated array.

An attacker that has the command key and is allowed to access cmdmon
(only localhost is allowed by default) could exploit this to crash
chronyd or possibly execute arbitrary code with the privileges of the
chronyd process.

cmdmon.c | 1 1 + 0 - 0 !
1 file changed, 1 insertion(+)

 cmdmon: fix initialization of allocated reply slots

When allocating memory to save unacknowledged replies to authenticated
command requests, the last "next" pointer was not initialized to NULL.
When all allocated reply slots were used, the next reply could be
written to an invalid memory instead of allocating a new slot for it.

An attacker that has the command key and is allowed to access cmdmon
(only localhost is allowed by default) could exploit this to crash
chronyd or possibly execute arbitrary code with the privileges of the
chronyd process.

ntp_core.c | 3 2 + 1 - 0 !
1 file changed, 2 insertions(+), 1 deletion(-)

 ntp: restrict authentication of server/peer to specified key
 When a server/peer was specified with a key number to enable
 authentication with a symmetric key, packets received from the
 server/peer were accepted if they were authenticated with any of
 the keys contained in the key file and not just the specified key.

 This allowed an attacker who knew one key of a client/peer to modify
 packets from its servers/peers that were authenticated with other
 keys in a man-in-the-middle (MITM) attack. For example, in a network
 where each NTP association had a separate key and all hosts had only
 keys they needed, a client of a server could not attack other clients
 of the server, but it could attack the server and also attack its own
 clients (i.e. modify packets from other servers).

 To not allow the server/peer to be authenticated with other keys
 extend the authentication test to check if the key ID in the received
 packet is equal to the configured key number. As a consequence, it's
 no longer possible to authenticate two peers to each other with two