Scientific Linux Security Update : ntp on SL6.x, SL7.x i386/x86_64

This script is Copyright (C) 2016-2017 Tenable Network Security, Inc.


Synopsis :

The remote Scientific Linux host is missing one or more security
updates.

Description :

Security Fix(es) :

- It was found that when NTP was configured in broadcast
mode, a remote attacker could broadcast packets with bad
authentication to all clients. The clients, upon
receiving the malformed packets, would break the
association with the broadcast server, causing them to
become out of sync over a longer period of time.
(CVE-2015-7979)

- A denial of service flaw was found in the way NTP
handled preemptable client associations. A remote
attacker could send several crypto NAK packets to a
victim client, each with a spoofed source address of an
existing associated peer, preventing that client from
synchronizing its time. (CVE-2016-1547)

- It was found that an ntpd client could be forced to
change from basic client/server mode to the interleaved
symmetric mode. A remote attacker could use a spoofed
packet that, when processed by an ntpd client, would
cause that client to reject all future legitimate server
responses, effectively disabling time synchronization on
that client. (CVE-2016-1548)

- A flaw was found in the way NTP's libntp performed
message authentication. An attacker able to observe the
timing of the comparison function used in packet
authentication could potentially use this flaw to
recover the message digest. (CVE-2016-1550)

- An out-of-bounds access flaw was found in the way ntpd
processed certain packets. An authenticated attacker
could use a crafted packet to create a peer association
with hmode of 7 and larger, which could potentially
(although highly unlikely) cause ntpd to crash.
(CVE-2016-2518)

The CVE-2016-1548 issue was discovered by Miroslav Lichvar (Red Hat).

See also :

http://www.nessus.org/u?d7be3f1b

Solution :

Update the affected packages.

Risk factor :

Medium / CVSS Base Score : 6.4
(CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 91644 ()

Bugtraq ID:

CVE ID: CVE-2015-7979
CVE-2016-1547
CVE-2016-1548
CVE-2016-1550
CVE-2016-2518

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