chrony before 1.31.2 and 2.x before 2.2.1 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a "skeleton key."

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - chrony before 1.31.2 and 2.x before 2.2.1 do not verify peer associations of symmetric keys when     authenticating packets, which might allow remote attackers to conduct impersonation attacks via an     arbitrary trusted key, aka a skeleton key. (CVE-2016-1567)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote NewStart CGSL host, running version MAIN 6.02, has chrony packages installed that are affected by multiple vulnerabilities:

  - Multiple integer overflows in pktlength.c in Chrony before 1.29 allow remote attackers to cause a denial     of service (crash) via a crafted (1) REQ_SUBNETS_ACCESSED or (2) REQ_CLIENT_ACCESSES command request to     the PKL_CommandLength function or crafted (3) RPY_SUBNETS_ACCESSED, (4) RPY_CLIENT_ACCESSES, (5)     RPY_CLIENT_ACCESSES_BY_INDEX, or (6) RPY_MANUAL_LIST command reply to the PKL_ReplyLength function, which     triggers an out-of-bounds read or buffer overflow. NOTE: versions 1.27 and 1.28 do not require     authentication to exploit. (CVE-2012-4502)

  - cmdmon.c in Chrony before 1.29 allows remote attackers to obtain potentially sensitive information from     stack memory via vectors related to (1) an invalid subnet in a RPY_SUBNETS_ACCESSED command to the     handle_subnets_accessed function or (2) a RPY_CLIENT_ACCESSES command to the handle_client_accesses     function when client logging is disabled, which causes uninitialized data to be included in a reply.
    (CVE-2012-4503)

  - Chrony before 1.29.1 has traffic amplification in cmdmon protocol (CVE-2014-0021)

  - Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of     service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access     with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.
    (CVE-2015-1821)

  - chrony before 1.31.1 does not initialize the last next pointer when saving unacknowledged replies to     command requests, which allows remote authenticated users to cause a denial of service (uninitialized     pointer dereference and daemon crash) or possibly execute arbitrary code via a large number of command     requests. (CVE-2015-1822)

  - chrony before 1.31.1 does not properly protect state variables in authenticated symmetric NTP     associations, which allows remote attackers with knowledge of NTP peering to cause a denial of service     (inability to synchronize) via random timestamps in crafted NTP data packets. (CVE-2015-1853)

  - chrony before 1.31.2 and 2.x before 2.2.1 do not verify peer associations of symmetric keys when     authenticating packets, which might allow remote attackers to conduct impersonation attacks via an     arbitrary trusted key, aka a skeleton key. (CVE-2016-1567)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

According to the version of the chrony package installed, the EulerOS installation on the remote host is affected by the following vulnerability :

  - chrony before 1.31.2 and 2.x before 2.2.1 do not verify     peer associations of symmetric keys when authenticating     packets, which might allow remote attackers to conduct     impersonation attacks via an arbitrary trusted key, aka     a 'skeleton key.'(CVE-2016-1567)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

It was discovered that Chrony, a versatile implementation of the Network Time Protocol, did not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a 'skeleton key.'

This update also resolves Debian bug #568492.

For Debian 7 'Wheezy', these problems have been fixed in version 1.24-3.1+deb7u4.

We recommend that you upgrade your chrony packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Security fix for CVE-2016-1567

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

chrony before 1.31.2 and 2.x before 2.2.1 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a 'skeleton key.'

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
219310	Linux Distros Unpatched Vulnerability : CVE-2016-1567	Nessus	Misc.	high
154559	NewStart CGSL MAIN 6.02 : chrony Multiple Vulnerabilities (NS-SA-2021-0127)	Nessus	NewStart CGSL Local Security Checks	critical
102245	EulerOS 2.0 SP2 : chrony (EulerOS-SA-2017-1158)	Nessus	Huawei Local Security Checks	high
95775	Debian DLA-742-1 : chrony security update	Nessus	Debian Local Security Checks	high
89565	Fedora 22 : chrony-2.1.1-2.fc22 (2016-6f783d1768)	Nessus	Fedora Local Security Checks	high
89561	Fedora 23 : chrony-2.1.1-2.fc23 (2016-6a0b0ab775)	Nessus	Fedora Local Security Checks	high
88724	Debian DLA-414-1 : chrony security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2016-1567

high

Tenable Plugins

high

critical

high

high

high

high

high