Vulnerabilities > CVE-2020-7919 - Improper Certificate Validation vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
Go before 1.12.16 and 1.13.x before 1.13.7 (and the crypto/cryptobyte package before 0.0.0-20200124225646-8b5121be2f68 for Go) allows attacks on clients (resulting in a panic) via a malformed X.509 certificate.
Vulnerable Configurations
Part | Description | Count |
---|---|---|
Application | 25 | |
Application | 1 | |
OS | 1 | |
OS | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Creating a Rogue Certificate Authority Certificate An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .
Nessus
NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-1_0-0292_GO.NASL description An update of the go package has been released. last seen 2020-05-18 modified 2020-05-13 plugin id 136553 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/136553 title Photon OS 1.0: Go 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(136553); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/15"); script_cve_id("CVE-2020-7919"); script_name(english:"Photon OS 1.0: Go 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 go 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: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: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-2020-7919"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/03/16"); 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:go"); 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:"go-1.11.13-4.ph1")) 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, "go"); }
NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-2_0-0238_GO.NASL description An update of the go package has been released. last seen 2020-05-08 modified 2020-05-05 plugin id 136327 published 2020-05-05 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136327 title Photon OS 2.0: Go PHSA-2020-2.0-0238 code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from VMware Security Advisory PHSA-2020-2.0-0238. The text # itself is copyright (C) VMware, Inc. include('compat.inc'); if (description) { script_id(136327); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/06"); script_cve_id("CVE-2020-7919"); script_name(english:"Photon OS 2.0: Go PHSA-2020-2.0-0238"); 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 go package has been released."); script_set_attribute(attribute:"see_also", value:"https://github.com/vmware/photon/wiki/Security-Updates-2-238.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: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: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-2020-7919"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/03/16"); script_set_attribute(attribute:"patch_publication_date", value:"2020/05/02"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/05"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:go"); 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:"go-1.13.5-2.ph2")) flag++; if (rpm_check(release:"PhotonOS-2.0", cpu:"x86_64", reference:"go-md2man-2.0.0-3.ph2")) flag++; if (rpm_check(release:"PhotonOS-2.0", cpu:"x86_64", reference:"go-md2man-debuginfo-2.0.0-3.ph2")) 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, "go"); }
NASL family Fedora Local Security Checks NASL id FEDORA_2020-12BC5B5597.NASL description - Rebase to go1.13.9 - Security fix for CVE-2020-7919 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 2020-04-16 modified 2020-04-10 plugin id 135369 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/135369 title Fedora 31 : golang (2020-12bc5b5597) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory FEDORA-2020-12bc5b5597. # include("compat.inc"); if (description) { script_id(135369); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/04/14"); script_cve_id("CVE-2020-7919"); script_xref(name:"FEDORA", value:"2020-12bc5b5597"); script_name(english:"Fedora 31 : golang (2020-12bc5b5597)"); 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: " - Rebase to go1.13.9 - Security fix for CVE-2020-7919 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-2020-12bc5b5597" ); script_set_attribute( attribute:"solution", value:"Update the affected golang package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/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: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:fedoraproject:fedora:golang"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/03/16"); script_set_attribute(attribute:"patch_publication_date", value:"2020/04/09"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/10"); 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:"golang-1.13.9-1.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, "golang"); }
NASL family PhotonOS Local Security Checks NASL id PHOTONOS_PHSA-2020-3_0-0087_GO.NASL description An update of the go package has been released. last seen 2020-05-18 modified 2020-05-13 plugin id 136575 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/136575 title Photon OS 3.0: Go PHSA-2020-3.0-0087 code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from VMware Security Advisory PHSA-2020-3.0-0087. The text # itself is copyright (C) VMware, Inc. include('compat.inc'); if (description) { script_id(136575); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/15"); script_cve_id("CVE-2020-7919"); script_name(english:"Photon OS 3.0: Go PHSA-2020-3.0-0087"); 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 go package has been released."); script_set_attribute(attribute:"see_also", value:"https://github.com/vmware/photon/wiki/Security-Updates-3.0-87.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: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: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-2020-7919"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"vuln_publication_date", value:"2020/03/16"); script_set_attribute(attribute:"patch_publication_date", value:"2020/05/09"); 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:go"); script_set_attribute(attribute:"cpe", value:"cpe:/o:vmware:photonos:3.0"); 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) 3\.0(\D|$)") audit(AUDIT_OS_NOT, "PhotonOS 3.0"); if (!get_kb_item("Host/PhotonOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "PhotonOS", cpu); flag = 0; if (rpm_check(release:"PhotonOS-3.0", cpu:"x86_64", reference:"go-1.13.3-2.ph3")) flag++; if (rpm_check(release:"PhotonOS-3.0", cpu:"x86_64", reference:"go-md2man-2.0.0-2.ph3")) flag++; if (rpm_check(release:"PhotonOS-3.0", cpu:"x86_64", reference:"go-md2man-debuginfo-2.0.0-2.ph3")) 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, "go"); }
References
- https://security.netapp.com/advisory/ntap-20200327-0001/
- https://www.debian.org/security/2021/dsa-4848
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S43VLYRURELDWX4D5RFOYBNFGO6CGBBC/
- https://groups.google.com/forum/#%21forum/golang-announce
- https://groups.google.com/forum/#%21topic/golang-announce/-sdUB4VEQkA
- https://groups.google.com/forum/#%21topic/golang-announce/Hsw4mHYc470