Vulnerabilities > CVE-2020-1747
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
A vulnerability was discovered in the PyYAML library in versions before 5.3.1, where it is susceptible to arbitrary code execution when it processes untrusted YAML files through the full_load method or with the FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this flaw. An attacker could use this flaw to execute arbitrary code on the system by abusing the python/object/new constructor.
Vulnerable Configurations
Part | Description | Count |
---|---|---|
Application | 15 | |
Application | 1 | |
OS | 4 | |
OS | 1 |
Nessus
NASL family Fedora Local Security Checks NASL id FEDORA_2020-BDB0BFA928.NASL description - New upstream release 5.3.1 (rhbz#1814882) - Fixes CVE-2020-1747 (rhbz#1807367,1809011) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-04-03 modified 2020-03-30 plugin id 134996 published 2020-03-30 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/134996 title Fedora 31 : PyYAML (2020-bdb0bfa928) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory FEDORA-2020-bdb0bfa928. # include("compat.inc"); if (description) { script_id(134996); script_version("1.3"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/04/02"); script_cve_id("CVE-2020-1747"); script_xref(name:"FEDORA", value:"2020-bdb0bfa928"); script_name(english:"Fedora 31 : PyYAML (2020-bdb0bfa928)"); script_summary(english:"Checks rpm output for the updated package."); script_set_attribute( attribute:"synopsis", value:"The remote Fedora host is missing a security update." ); script_set_attribute( attribute:"description", value: " - New upstream release 5.3.1 (rhbz#1814882) - Fixes CVE-2020-1747 (rhbz#1807367,1809011) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. 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://bodhi.fedoraproject.org/updates/FEDORA-2020-bdb0bfa928" ); script_set_attribute( attribute:"solution", value:"Update the affected PyYAML package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C"); 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:H/I:H/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:fedoraproject:fedora:PyYAML"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/03/24"); script_set_attribute(attribute:"patch_publication_date", value:"2020/03/27"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/03/30"); 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:"Fedora Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/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/RedHat/release"); if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora"); os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release); if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora"); os_ver = os_ver[1]; if (! preg(pattern:"^31([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 31", "Fedora " + os_ver); if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu); flag = 0; if (rpm_check(release:"FC31", reference:"PyYAML-5.3.1-1.fc31")) flag++; if (flag) { security_report_v4( port : 0, severity : SECURITY_HOLE, 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, "PyYAML"); }
NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-1_0-0290_PYYAML.NASL description An update of the PyYAML package has been released. last seen 2020-05-03 modified 2020-04-29 plugin id 136104 published 2020-04-29 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136104 title Photon OS 1.0: Pyyaml PHSA-2020-1.0-0290 NASL family SuSE Local Security Checks NASL id SUSE_SU-2020-0959-1.NASL description This update for python-PyYAML fixes the following issues : CVE-2020-1747: Fixed an arbitrary code execution when YAML files are parsed by FullLoader (bsc#1165439). Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-04-16 modified 2020-04-10 plugin id 135390 published 2020-04-10 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135390 title SUSE SLED15 / SLES15 Security Update : python-PyYAML (SUSE-SU-2020:0959-1) NASL family SuSE Local Security Checks NASL id OPENSUSE-2020-630.NASL description This update for python-PyYAML fixes the following issues : - CVE-2020-1747: Fixed an arbitrary code execution when YAML files are parsed by FullLoader (bsc#1165439). This update was imported from the SUSE:SLE-15-SP1:Update update project. last seen 2020-05-15 modified 2020-05-11 plugin id 136456 published 2020-05-11 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136456 title openSUSE Security Update : python-PyYAML (openSUSE-2020-630) NASL family SuSE Local Security Checks NASL id OPENSUSE-2020-507.NASL description This update for python-PyYAML fixes the following issues : - CVE-2020-1747: Fixed an arbitrary code execution when YAML files are parsed by FullLoader (bsc#1165439). This update was imported from the SUSE:SLE-15-SP1:Update update project. last seen 2020-04-17 modified 2020-04-14 plugin id 135451 published 2020-04-14 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135451 title openSUSE Security Update : python-PyYAML (openSUSE-2020-507) NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-3_0-0080_PYYAML.NASL description An update of the PyYAML package has been released. last seen 2020-04-30 modified 2020-04-21 plugin id 135789 published 2020-04-21 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135789 title Photon OS 3.0: Pyyaml PHSA-2020-3.0-0080 NASL family Fedora Local Security Checks NASL id FEDORA_2020-40C35D7B37.NASL description - New upstream release 5.3.1 (rhbz#1814882) - Fixes CVE-2020-1747 (rhbz#1807367,1809011) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-04-03 modified 2020-03-30 plugin id 134991 published 2020-03-30 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/134991 title Fedora 30 : PyYAML (2020-40c35d7b37) NASL family FreeBSD Local Security Checks NASL id FREEBSD_PKG_AAE8FECF888E11EA971408002718DE91.NASL description Riccardo Schirone (https://github.com/ret2libc) reports : In FullLoader python/object/new constructor, implemented by construct_python_object_apply, has support for setting the state of a deserialized instance through the set_python_instance_state method. After setting the state, some operations are performed on the instance to complete its initialization, however it is possible for an attacker to set the instance last seen 2020-05-03 modified 2020-04-28 plugin id 136021 published 2020-04-28 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136021 title FreeBSD : py-yaml -- FullLoader (still) exploitable for arbitrary command execution (aae8fecf-888e-11ea-9714-08002718de91) NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-2_0-0229_PYYAML.NASL description An update of the PyYAML package has been released. last seen 2020-04-30 modified 2020-04-22 plugin id 135866 published 2020-04-22 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135866 title Photon OS 2.0: Pyyaml PHSA-2020-2.0-0229 NASL family SuSE Local Security Checks NASL id SUSE_SU-2020-1285-1.NASL description This update for python-PyYAML fixes the following issues : CVE-2020-1747: Fixed an arbitrary code execution when YAML files are parsed by FullLoader (bsc#1165439). Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-05-31 modified 2020-05-22 plugin id 136784 published 2020-05-22 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136784 title SUSE SLES12 Security Update : python-PyYAML (SUSE-SU-2020:1285-1)
References
- http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00017.html
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1747
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1747
- https://github.com/yaml/pyyaml/pull/386
- https://github.com/yaml/pyyaml/pull/386
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7PPAS6C4SZRDQLR7C22A5U3QOLXY33JX/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7PPAS6C4SZRDQLR7C22A5U3QOLXY33JX/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K5HEPD7LEVDPCITY5IMDYWXUMX37VFMY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K5HEPD7LEVDPCITY5IMDYWXUMX37VFMY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MMQXSZXNJT6ERABJZAAICI3DQSQLCP3D/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MMQXSZXNJT6ERABJZAAICI3DQSQLCP3D/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WORRFHPQVAFKKXXWLSSW6XKUYLWM6CSH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WORRFHPQVAFKKXXWLSSW6XKUYLWM6CSH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZBJA3SGNJKCAYPSHOHWY3KBCWNM5NYK2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZBJA3SGNJKCAYPSHOHWY3KBCWNM5NYK2/
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html