| Description: | Summary:
The remote host is missing an update for the 'ntp'
package(s) announced via the referenced advisory.
Vulnerability Insight:
The Network Time Protocol (NTP) is used to
synchronize a computer's time with another referenced time source. These packages
include the ntpd service which continuously adjusts system time and utilities
used to query and configure the ntpd service.
It was found that because NTP's access control was based on a source IP
address, an attacker could bypass source IP restrictions and send
malicious control and configuration packets by spoofing ::1 addresses.
(CVE-2014-9298, CVE-2014-9751)
A denial of service flaw was found in the way NTP hosts that were peering
with each other authenticated themselves before updating their internal
state variables. An attacker could send packets to one peer host, which
could cascade to other peers, and stop the synchronization process among
the reached peers. (CVE-2015-1799)
A flaw was found in the way the ntp-keygen utility generated MD5 symmetric
keys on big-endian systems. An attacker could possibly use this flaw to
guess generated MD5 keys, which could then be used to spoof an NTP client
or server. (CVE-2015-3405)
A stack-based buffer overflow was found in the way the NTP autokey protocol
was implemented. When an NTP client decrypted a secret received from an NTP
server, it could cause that client to crash. (CVE-2014-9297, CVE-2014-9750)
It was found that ntpd did not check whether a Message Authentication Code
(MAC) was present in a received packet when ntpd was configured to use
symmetric cryptographic keys. A man-in-the-middle attacker could use this
flaw to send crafted packets that would be accepted by a client or a peer
without the attacker knowing the symmetric key. (CVE-2015-1798)
The CVE-2015-1798 and CVE-2015-1799 issues were discovered by Miroslav
Lichvar of Red Hat.
Bug fixes:
* The ntpd service truncated symmetric keys specified in the key file to 20
bytes. As a consequence, it was impossible to configure NTP authentication
to work with peers that use longer keys. With this update, the maximum key
length has been changed to 32 bytes. (BZ#1191111)
* The ntpd service could previously join multicast groups only when
starting, which caused problems if ntpd was started during system boot
before network was configured. With this update, ntpd attempts to join
multicast groups every time network configuration is changed. (BZ#1207014)
* Previously, the ntp-keygen utility used the exponent of 3 when generating
RSA keys. Consequently, generating RSA keys failed when FIPS mode was
enabled. With this update, ntp-keygen has been modified to use the exponent
of 65537, and generating keys in FIPS mode now works as expected.
(BZ#11 ...
Description truncated, please see the referenced URL(s) for more information.
Affected Software/OS:
ntp on Red Hat Enterprise Linux Server (v. 7)
Solution:
Please Install the Updated Packages.
CVSS Score:
6.8
CVSS Vector:
AV:N/AC:M/Au:N/C:P/I:P/A:P
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