Vulnerabilities > CVE-2016-10937 - Improper Certificate Validation vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
HIGH Availability impact
NONE Summary
IMAPFilter through 2.6.12 does not validate the hostname in an SSL certificate.
Vulnerable Configurations
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 Fedora Local Security Checks NASL id FEDORA_2019-A6C5D70BDE.NASL description New upstream release: fixes CVE-2016-10937 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 2020-06-01 modified 2020-06-02 plugin id 131339 published 2019-11-27 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/131339 title Fedora 31 : imapfilter (2019-a6c5d70bde) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory FEDORA-2019-a6c5d70bde. # include("compat.inc"); if (description) { script_id(131339); script_version("1.2"); script_cvs_date("Date: 2019/12/09"); script_cve_id("CVE-2016-10937"); script_xref(name:"FEDORA", value:"2019-a6c5d70bde"); script_name(english:"Fedora 31 : imapfilter (2019-a6c5d70bde)"); 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: fixes CVE-2016-10937 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-2019-a6c5d70bde" ); script_set_attribute( attribute:"solution", value:"Update the affected imapfilter package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N"); 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:H/A:N"); 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:imapfilter"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/08"); script_set_attribute(attribute:"patch_publication_date", value:"2019/11/27"); script_set_attribute(attribute:"plugin_publication_date", value:"2019/11/27"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2019 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:"imapfilter-2.6.15-1.fc31")) 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, "imapfilter"); }
NASL family SuSE Local Security Checks NASL id OPENSUSE-2020-673.NASL description This update for imapfilter fixes the following issues : Imapfilter was updated to version 2.6.16 including the following security issue : - CVE-2016-10937: Added Support for SSL hostname validation (boo#1149931). last seen 2020-05-31 modified 2020-05-26 plugin id 136873 published 2020-05-26 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136873 title openSUSE Security Update : imapfilter (openSUSE-2020-673) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from openSUSE Security Update openSUSE-2020-673. # # The text description of this plugin is (C) SUSE LLC. # include("compat.inc"); if (description) { script_id(136873); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/28"); script_cve_id("CVE-2016-10937"); script_name(english:"openSUSE Security Update : imapfilter (openSUSE-2020-673)"); script_summary(english:"Check for the openSUSE-2020-673 patch"); script_set_attribute( attribute:"synopsis", value:"The remote openSUSE host is missing a security update." ); script_set_attribute( attribute:"description", value: "This update for imapfilter fixes the following issues : Imapfilter was updated to version 2.6.16 including the following security issue : - CVE-2016-10937: Added Support for SSL hostname validation (boo#1149931)." ); script_set_attribute( attribute:"see_also", value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1149931" ); script_set_attribute( attribute:"solution", value:"Update the affected imapfilter packages." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N"); 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:H/A:N"); 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:novell:opensuse:imapfilter"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:imapfilter-debuginfo"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:imapfilter-debugsource"); script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.1"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/08"); script_set_attribute(attribute:"patch_publication_date", value:"2020/05/22"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/26"); 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:"SuSE Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/SuSE/release", "Host/SuSE/rpm-list", "Host/cpu"); 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/SuSE/release"); if (isnull(release) || release =~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "openSUSE"); if (release !~ "^(SUSE15\.1)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.1", release); if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); ourarch = get_kb_item("Host/cpu"); if (!ourarch) audit(AUDIT_UNKNOWN_ARCH); if (ourarch !~ "^(x86_64)$") audit(AUDIT_ARCH_NOT, "x86_64", ourarch); flag = 0; if ( rpm_check(release:"SUSE15.1", reference:"imapfilter-2.6.16-lp151.3.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"imapfilter-debuginfo-2.6.16-lp151.3.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"imapfilter-debugsource-2.6.16-lp151.3.3.1") ) flag++; if (flag) { if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get()); else security_warning(0); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "imapfilter / imapfilter-debuginfo / imapfilter-debugsource"); }
NASL family Fedora Local Security Checks NASL id FEDORA_2019-90925DD5AA.NASL description New upstream release: fixes CVE-2016-10937 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 2020-06-01 modified 2020-06-02 plugin id 131338 published 2019-11-27 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/131338 title Fedora 30 : imapfilter (2019-90925dd5aa) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory FEDORA-2019-90925dd5aa. # include("compat.inc"); if (description) { script_id(131338); script_version("1.2"); script_cvs_date("Date: 2019/12/09"); script_cve_id("CVE-2016-10937"); script_xref(name:"FEDORA", value:"2019-90925dd5aa"); script_name(english:"Fedora 30 : imapfilter (2019-90925dd5aa)"); 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: fixes CVE-2016-10937 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-2019-90925dd5aa" ); script_set_attribute( attribute:"solution", value:"Update the affected imapfilter package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N"); 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:H/A:N"); 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:imapfilter"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/08"); script_set_attribute(attribute:"patch_publication_date", value:"2019/11/26"); script_set_attribute(attribute:"plugin_publication_date", value:"2019/11/27"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2019 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:"^30([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 30", "Fedora " + os_ver); if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu); flag = 0; if (rpm_check(release:"FC30", reference:"imapfilter-2.6.15-1.fc30")) 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, "imapfilter"); }
NASL family Debian Local Security Checks NASL id DEBIAN_DLA-1976.NASL description The imapfilter tool, a utility for scripting IMAP operations in lua, lacked server name / certificate peer hostname validation support. For Debian 8 last seen 2020-06-01 modified 2020-06-02 plugin id 130405 published 2019-10-31 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130405 title Debian DLA-1976-1 : imapfilter security update code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Debian Security Advisory DLA-1976-1. The text # itself is copyright (C) Software in the Public Interest, Inc. # include("compat.inc"); if (description) { script_id(130405); script_version("1.3"); script_cvs_date("Date: 2019/12/17"); script_cve_id("CVE-2016-10937"); script_name(english:"Debian DLA-1976-1 : imapfilter security update"); script_summary(english:"Checks dpkg output for the updated package."); script_set_attribute( attribute:"synopsis", value:"The remote Debian host is missing a security update." ); script_set_attribute( attribute:"description", value: "The imapfilter tool, a utility for scripting IMAP operations in lua, lacked server name / certificate peer hostname validation support. For Debian 8 'Jessie', this problem has been fixed in version 1:2.5.2-2+deb8u1. We recommend that you upgrade your imapfilter 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/2019/10/msg00040.html" ); script_set_attribute( attribute:"see_also", value:"https://packages.debian.org/source/jessie/imapfilter" ); script_set_attribute( attribute:"solution", value:"Upgrade the affected imapfilter package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N"); 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:H/A:N"); 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:imapfilter"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/08"); script_set_attribute(attribute:"patch_publication_date", value:"2019/10/30"); script_set_attribute(attribute:"plugin_publication_date", value:"2019/10/31"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2019 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:"imapfilter", reference:"1:2.5.2-2+deb8u1")) 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");
References
- https://bugs.debian.org/939702
- https://github.com/lefcha/imapfilter/issues/142
- https://lists.debian.org/debian-lts-announce/2019/10/msg00040.html
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00042.html
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00002.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GBNDFMAIUA6PQMV2P6OKIP7JZQEWX7D2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IQUH2TOCNEST7JB2RJVVJT3RZS5XZCFZ/