Vulnerabilities > CVE-2020-11868 - Origin Validation Error vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
ntpd in ntp before 4.2.8p14 and 4.3.x before 4.3.100 allows an off-path attacker to block unauthenticated synchronization via a server mode packet with a spoofed source IP address, because transmissions are rescheduled even when a packet lacks a valid origin timestamp.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- JSON Hijacking (aka JavaScript Hijacking) An attacker targets a system that uses JavaScript Object Notation (JSON) as a transport mechanism between the client and the server (common in Web 2.0 systems using AJAX) to steal possibly confidential information transmitted from the server back to the client inside the JSON object by taking advantage of the loophole in the browser's Same Origin Policy that does not prohibit JavaScript from one website to be included and executed in the context of another website. An attacker gets the victim to visit his or her malicious page that contains a script tag whose source points to the vulnerable system with a URL that requests a response from the server containing a JSON object with possibly confidential information. The malicious page also contains malicious code to capture the JSON object returned by the server before any other processing on it can take place, typically by overriding the JavaScript function used to create new objects. This hook allows the malicious code to get access to the creation of each object and transmit the possibly sensitive contents of the captured JSON object to the attackers' server. There is nothing in the browser's security model to prevent the attackers' malicious JavaScript code (originating from attacker's domain) to set up an environment (as described above) to intercept a JSON object response (coming from the vulnerable target system's domain), read its contents and transmit to the attackers' controlled site. The same origin policy protects the domain object model (DOM), but not the JSON.
- Cache Poisoning An attacker exploits the functionality of cache technologies to cause specific data to be cached that aids the attackers' objectives. This describes any attack whereby an attacker places incorrect or harmful material in cache. The targeted cache can be an application's cache (e.g. a web browser cache) or a public cache (e.g. a DNS or ARP cache). Until the cache is refreshed, most applications or clients will treat the corrupted cache value as valid. This can lead to a wide range of exploits including redirecting web browsers towards sites that install malware and repeatedly incorrect calculations based on the incorrect value.
- DNS Cache Poisoning A domain name server translates a domain name (such as www.example.com) into an IP address that Internet hosts use to contact Internet resources. An attacker modifies a public DNS cache to cause certain names to resolve to incorrect addresses that the attacker specifies. The result is that client applications that rely upon the targeted cache for domain name resolution will be directed not to the actual address of the specified domain name but to some other address. Attackers can use this to herd clients to sites that install malware on the victim's computer or to masquerade as part of a Pharming attack.
- Exploitation of Session Variables, Resource IDs and other Trusted Credentials Attacks on session IDs and resource IDs take advantage of the fact that some software accepts user input without verifying its authenticity. For example, a message queuing system that allows service requesters to post messages to its queue through an open channel (such as anonymous FTP), authorization is done through checking group or role membership contained in the posted message. However, there is no proof that the message itself, the information in the message (such group or role membership), or indeed the process that wrote the message to the queue are authentic and authorized to do so. Many server side processes are vulnerable to these attacks because the server to server communications have not been analyzed from a security perspective or the processes "trust" other systems because they are behind a firewall. In a similar way servers that use easy to guess or spoofable schemes for representing digital identity can also be vulnerable. Such systems frequently use schemes without cryptography and digital signatures (or with broken cryptography). Session IDs may be guessed due to insufficient randomness, poor protection (passed in the clear), lack of integrity (unsigned), or improperly correlation with access control policy enforcement points. Exposed configuration and properties files that contain system passwords, database connection strings, and such may also give an attacker an edge to identify these identifiers. The net result is that spoofing and impersonation is possible leading to an attacker's ability to break authentication, authorization, and audit controls on the system.
- Application API Message Manipulation via Man-in-the-Middle An attacker manipulates either egress or ingress data from a client within an application framework in order to change the content of messages. Performing this attack can allow the attacker to gain unauthorized privileges within the application, or conduct attacks such as phishing, deceptive strategies to spread malware, or traditional web-application attacks. The techniques require use of specialized software that allow the attacker to man-in-the-middle communications between the web browser and the remote system. Despite the use of MITM software, the attack is actually directed at the server, as the client is one node in a series of content brokers that pass information along to the application framework. Additionally, it is not true "Man-in-the-Middle" attack at the network layer, but an application-layer attack the root cause of which is the master applications trust in the integrity of code supplied by the client.
Nessus
NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-2_0-0239_NTP.NASL description An update of the ntp package has been released. last seen 2020-05-15 modified 2020-05-07 plugin id 136409 published 2020-05-07 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136409 title Photon OS 2.0: Ntp PHSA-2020-2.0-0239 code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from VMware Security Advisory PHSA-2020-2.0-0239. The text # itself is copyright (C) VMware, Inc. include('compat.inc'); if (description) { script_id(136409); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/13"); script_cve_id("CVE-2020-11868"); script_name(english:"Photon OS 2.0: Ntp PHSA-2020-2.0-0239"); script_set_attribute(attribute:"synopsis", value: "The remote PhotonOS host is missing multiple security updates."); script_set_attribute(attribute:"description", value: "An update of the ntp package has been released."); script_set_attribute(attribute:"see_also", value:"https://github.com/vmware/photon/wiki/Security-Updates-2-239.md"); script_set_attribute(attribute:"solution", value: "Update the affected Linux packages."); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-11868"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/17"); script_set_attribute(attribute:"patch_publication_date", value:"2020/05/07"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/07"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:ntp"); script_set_attribute(attribute:"cpe", value:"cpe:/o:vmware:photonos:2.0"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_family(english:"PhotonOS Local Security Checks"); script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/PhotonOS/release", "Host/PhotonOS/rpm-list"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("rpm.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); release = get_kb_item("Host/PhotonOS/release"); if (isnull(release) || release !~ "^VMware Photon") audit(AUDIT_OS_NOT, "PhotonOS"); if (release !~ "^VMware Photon (?:Linux|OS) 2\.0(\D|$)") audit(AUDIT_OS_NOT, "PhotonOS 2.0"); if (!get_kb_item("Host/PhotonOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "PhotonOS", cpu); flag = 0; if (rpm_check(release:"PhotonOS-2.0", cpu:"x86_64", reference:"ntp-4.2.8p14-1.ph2")) flag++; if (rpm_check(release:"PhotonOS-2.0", cpu:"x86_64", reference:"ntp-debuginfo-4.2.8p14-1.ph2")) flag++; if (rpm_check(release:"PhotonOS-2.0", cpu:"x86_64", reference:"ntp-perl-4.2.8p14-1.ph2")) flag++; if (flag) { security_report_v4( port : 0, severity : SECURITY_WARNING, extra : rpm_report_get() ); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "ntp"); }
NASL family Misc. NASL id NTP_4_2_8P14.NASL description The version of the remote NTP server is 4.x prior to 4.2.8p14, or is 4.3.x prior to 4.3.100. It is, therefore, affected by a denial of service vulnerability due to a flaw in handling unauthenticated synchronization traffic. An authenticated attacker can exploit this issue to cause denial of service. Note that Nessus has not tested for this issue but has instead relied only on the application last seen 2020-04-30 modified 2020-04-23 plugin id 135920 published 2020-04-23 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135920 title Network Time Protocol Daemon (ntpd) 4.x < 4.2.8p14 / 4.3.x < 4.3.100 DoS code # # (C) Tenable Network Security, Inc. # include('compat.inc'); if (description) { script_id(135920); script_version("1.5"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/07/10"); script_cve_id("CVE-2020-11868"); script_xref(name:"IAVA", value:"2020-A-0167-S"); script_name(english:"Network Time Protocol Daemon (ntpd) 4.x < 4.2.8p14 / 4.3.x < 4.3.100 DoS"); script_summary(english:"Checks for a vulnerable NTP server."); script_set_attribute(attribute:"synopsis", value: "The remote NTP server is affected by a denial of service vulnerability."); script_set_attribute(attribute:"description", value: "The version of the remote NTP server is 4.x prior to 4.2.8p14, or is 4.3.x prior to 4.3.100. It is, therefore, affected by a denial of service vulnerability due to a flaw in handling unauthenticated synchronization traffic. An authenticated attacker can exploit this issue to cause denial of service. Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number."); script_set_attribute(attribute:"see_also", value:"http://support.ntp.org/bin/view/Main/NtpBug3592"); script_set_attribute(attribute:"see_also", value:"https://bugs.ntp.org/show_bug.cgi?id=3445"); script_set_attribute(attribute:"solution", value: "Upgrade to NTP version 4.2.8p14, 4.3.100 or later."); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-11868"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/17"); script_set_attribute(attribute:"patch_publication_date", value:"2020/04/17"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/23"); script_set_attribute(attribute:"potential_vulnerability", value:"true"); script_set_attribute(attribute:"plugin_type", value:"remote"); script_set_attribute(attribute:"cpe", value:"cpe:/a:ntp:ntp"); script_set_attribute(attribute:"stig_severity", value:"I"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_family(english:"Misc."); script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_dependencies("ntp_open.nasl"); script_require_keys("NTP/Running", "Settings/ParanoidReport"); exit(0); } include('audit.inc'); include('global_settings.inc'); include('misc_func.inc'); # Paranoia check if (report_paranoia < 2) audit(AUDIT_PARANOID); # Make sure NTP server is running get_kb_item_or_exit('NTP/Running'); app_name = 'NTP Server'; port = get_kb_item('Services/udp/ntp'); if (empty_or_null(port)) port = 123; version = get_kb_item_or_exit('Services/ntp/version'); if (version == 'unknown') audit(AUDIT_UNKNOWN_APP_VER, app_name); match = pregmatch(string:version, pattern:"^([0-9]+\.[0-9]+\.[0-9p]+)"); if (empty_or_null(match)) audit(AUDIT_UNKNOWN_APP_VER, app_name); ver = match[1]; verfields = split(ver, sep:'.', keep:FALSE); major = int(verfields[0]); minor = int(verfields[1]); if ('p' >< verfields[2]) { revpatch = split(verfields[2], sep:'p', keep:FALSE); rev = int(revpatch[0]); patch = int(revpatch[1]); } else { rev = verfields[2]; patch = 0; } # This vulnerability affects NTP 4.x < 4.2.8p14 # Check for vuln, else audit out. if ( (major == 4 && minor < 2) || (major == 4 && minor == 2 && rev < 8) || (major == 4 && minor == 2 && rev == 8 && patch < 14) ) { fix = '4.2.8p14'; } else if (major == 4 && minor == 3 && rev < 100) { fix = '4.3.100'; } else audit(AUDIT_INST_VER_NOT_VULN, app_name, version); report = '\n Installed version : ' + version + '\n Fixed version : ' + fix + '\n'; security_report_v4( port : port, proto : 'udp', extra : report, severity : SECURITY_WARNING ); exit(0);
NASL family Debian Local Security Checks NASL id DEBIAN_DLA-2201.NASL description A Denial of Service (DoS) vulnerability was discovered in the network time protocol server/client, ntp. ntp allowed an last seen 2020-05-12 modified 2020-05-07 plugin id 136366 published 2020-05-07 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136366 title Debian DLA-2201-1 : ntp security update code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Debian Security Advisory DLA-2201-1. The text # itself is copyright (C) Software in the Public Interest, Inc. # include("compat.inc"); if (description) { script_id(136366); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/11"); script_cve_id("CVE-2020-11868"); script_name(english:"Debian DLA-2201-1 : ntp security update"); script_summary(english:"Checks dpkg output for the updated packages."); script_set_attribute( attribute:"synopsis", value:"The remote Debian host is missing a security update." ); script_set_attribute( attribute:"description", value: "A Denial of Service (DoS) vulnerability was discovered in the network time protocol server/client, ntp. ntp allowed an 'off-path' attacker to block unauthenticated synchronisation via a server mode packet with a spoofed source IP address because transmissions were rescheduled even if a packet lacked a valid 'origin timestamp' For Debian 8 'Jessie', this issue has been fixed in ntp version 1:4.2.6.p5+dfsg-7+deb8u3. We recommend that you upgrade your ntp 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." ); script_set_attribute( attribute:"see_also", value:"https://lists.debian.org/debian-lts-announce/2020/05/msg00004.html" ); script_set_attribute( attribute:"see_also", value:"https://packages.debian.org/source/jessie/ntp" ); script_set_attribute( attribute:"solution", value:"Upgrade the affected ntp, ntp-doc, and ntpdate packages." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ntp"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ntp-doc"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ntpdate"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/17"); script_set_attribute(attribute:"patch_publication_date", value:"2020/05/05"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/07"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Debian Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l"); exit(0); } include("audit.inc"); include("debian_package.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian"); if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING); flag = 0; if (deb_check(release:"8.0", prefix:"ntp", reference:"1:4.2.6.p5+dfsg-7+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"ntp-doc", reference:"1:4.2.6.p5+dfsg-7+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"ntpdate", reference:"1:4.2.6.p5+dfsg-7+deb8u3")) flag++; if (flag) { if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get()); else security_warning(0); exit(0); } else audit(AUDIT_HOST_NOT, "affected");
NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-1_0-0292_NTP.NASL description An update of the ntp package has been released. last seen 2020-05-18 modified 2020-05-13 plugin id 136557 published 2020-05-13 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136557 title Photon OS 1.0: Ntp PHSA-2020-1.0-0292 code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from VMware Security Advisory PHSA-2020-1.0-0292. The text # itself is copyright (C) VMware, Inc. include('compat.inc'); if (description) { script_id(136557); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/15"); script_cve_id("CVE-2020-11868"); script_name(english:"Photon OS 1.0: Ntp PHSA-2020-1.0-0292"); script_set_attribute(attribute:"synopsis", value: "The remote PhotonOS host is missing multiple security updates."); script_set_attribute(attribute:"description", value: "An update of the ntp package has been released."); script_set_attribute(attribute:"see_also", value:"https://github.com/vmware/photon/wiki/Security-Updates-1.0-292.md"); script_set_attribute(attribute:"solution", value: "Update the affected Linux packages."); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-11868"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/17"); script_set_attribute(attribute:"patch_publication_date", value:"2020/05/10"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/13"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:ntp"); script_set_attribute(attribute:"cpe", value:"cpe:/o:vmware:photonos:1.0"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_family(english:"PhotonOS Local Security Checks"); script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/PhotonOS/release", "Host/PhotonOS/rpm-list"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("rpm.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); release = get_kb_item("Host/PhotonOS/release"); if (isnull(release) || release !~ "^VMware Photon") audit(AUDIT_OS_NOT, "PhotonOS"); if (release !~ "^VMware Photon (?:Linux|OS) 1\.0(\D|$)") audit(AUDIT_OS_NOT, "PhotonOS 1.0"); if (!get_kb_item("Host/PhotonOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "PhotonOS", cpu); flag = 0; if (rpm_check(release:"PhotonOS-1.0", cpu:"x86_64", reference:"ntp-4.2.8p14-1.ph1")) flag++; if (rpm_check(release:"PhotonOS-1.0", cpu:"x86_64", reference:"ntp-debuginfo-4.2.8p14-1.ph1")) flag++; if (flag) { security_report_v4( port : 0, severity : SECURITY_WARNING, extra : rpm_report_get() ); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "ntp"); }
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00005.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00044.html
- http://support.ntp.org/bin/view/Main/NtpBug3592
- https://bugzilla.redhat.com/show_bug.cgi?id=1716665
- https://lists.debian.org/debian-lts-announce/2020/05/msg00004.html
- https://security.gentoo.org/glsa/202007-12
- https://security.netapp.com/advisory/ntap-20200424-0002/
- https://www.oracle.com//security-alerts/cpujul2021.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00005.html
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://security.netapp.com/advisory/ntap-20200424-0002/
- https://security.gentoo.org/glsa/202007-12
- https://lists.debian.org/debian-lts-announce/2020/05/msg00004.html
- https://bugzilla.redhat.com/show_bug.cgi?id=1716665
- http://support.ntp.org/bin/view/Main/NtpBug3592
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00044.html