Chrony before 1.29.1 has traffic amplification in cmdmon protocol

The remote NewStart CGSL host, running version MAIN 6.06, has chrony packages installed that are affected by multiple vulnerabilities:

  - 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)

  - The read_from_cmd_socket function in cmdmon.c in chronyd in Chrony before 1.23.1, and 1.24-pre1, allows     remote attackers to cause a denial of service (CPU and bandwidth consumption) by sending a spoofed cmdmon     packet that triggers a continuous exchange of NOHOSTACCESS messages between two daemons, a related issue     to CVE-2009-3563. (CVE-2010-0292)

  - The client logging functionality in chronyd in Chrony before 1.23.1 does not restrict the amount of memory     used for storage of client information, which allows remote attackers to cause a denial of service (memory     consumption) via spoofed (1) NTP or (2) cmdmon packets. (CVE-2010-0293)

  - chronyd in Chrony before 1.23.1, and possibly 1.24-pre1, generates a syslog message for each unauthorized     cmdmon packet, which allows remote attackers to cause a denial of service (disk consumption) via a large     number of invalid packets. (CVE-2010-0294)

  - 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)

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

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

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

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.

The remote NewStart CGSL host, running version CORE 5.05 / MAIN 5.05, 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)

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

The remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, 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)

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

It was reported that the cmdmon protocol implemented in chrony was found to be vulnerable to DDoS attacks using traffic amplification. By default, commands are allowed only from localhost, but it's possible to configure chronyd to allow commands from any address. This could allow a remote attacker to cause a DoS, which could cause excessive resource usage.

This update fixes the following security vulnerability :

  - Modify chronyc protocol to prevent amplification attacks     (CVE-2014-0021) (incompatible with previous protocol     version, chronyc supports both)

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.

ID	Name	Product	Family	Severity
266273	NewStart CGSL MAIN 6.06 : chrony Multiple Vulnerabilities (NS-SA-2025-0212)	Nessus	NewStart CGSL Local Security Checks	high
218138	Linux Distros Unpatched Vulnerability : CVE-2014-0021	Nessus	Misc.	high
154559	NewStart CGSL MAIN 6.02 : chrony Multiple Vulnerabilities (NS-SA-2021-0127)	Nessus	NewStart CGSL Local Security Checks	critical
143974	NewStart CGSL CORE 5.05 / MAIN 5.05 : chrony Multiple Vulnerabilities (NS-SA-2020-0112)	Nessus	NewStart CGSL Local Security Checks	high
136904	NewStart CGSL CORE 5.04 / MAIN 5.04 : chrony Multiple Vulnerabilities (NS-SA-2020-0027)	Nessus	NewStart CGSL Local Security Checks	high
78309	Amazon Linux AMI : chrony (ALAS-2014-366)	Nessus	Amazon Linux Local Security Checks	high
72593	Fedora 19 : chrony-1.29.1-1.fc19 (2014-1916)	Nessus	Fedora Local Security Checks	low
72358	Fedora 20 : chrony-1.29.1-1.fc20 (2014-1943)	Nessus	Fedora Local Security Checks	low

Detections

Analytics

CVE-2014-0021

high

Tenable Plugins

high

high

critical

high

high

high

low

low