Vulnerabilities > CVE-2018-20187 - Key Management Errors vulnerability in Botan Project Botan

047910
CVSS 5.9 - MEDIUM
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
NONE
Availability impact
NONE
network
high complexity
botan-project
CWE-320
nessus

Summary

A side-channel issue was discovered in Botan before 2.9.0. An attacker capable of precisely measuring the time taken for ECC key generation may be able to derive information about the high bits of the secret key, as the function to derive the public point from the secret scalar uses an unblinded Montgomery ladder whose loop iteration count depends on the bitlength of the secret. This issue affects only key generation, not ECDSA signatures or ECDH key agreement.

Vulnerable Configurations

Part Description Count
Application
Botan_Project
222

Common Weakness Enumeration (CWE)

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2019-E0F5A82082.NASL
    descriptionUpdate to 2.9.0 including security fix for CVE-2018-20187 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 seen2020-06-01
    modified2020-06-02
    plugin id122324
    published2019-02-20
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/122324
    titleFedora 29 : botan2 (2019-e0f5a82082)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2019-e0f5a82082.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(122324);
      script_version("1.4");
      script_cvs_date("Date: 2020/02/10");
    
      script_cve_id("CVE-2018-20187");
      script_xref(name:"FEDORA", value:"2019-e0f5a82082");
    
      script_name(english:"Fedora 29 : botan2 (2019-e0f5a82082)");
      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:
    "Update to 2.9.0 including security fix for CVE-2018-20187
    
    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-e0f5a82082"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected botan2 package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/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:H/PR:N/UI:N/S:U/C:H/I:N/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:botan2");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:29");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/03/08");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/02/20");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/20");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2019-2020 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:"^29([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 29", "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:"FC29", reference:"botan2-2.9.0-1.fc29")) 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, "botan2");
    }
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_D8E7E85417FA11E9BEF66805CA2FA271.NASL
    descriptionbotan2 developers reports : A timing side channel during ECC key generation could leak information about the high bits of the secret scalar. Such information allows an attacker to perform a brute-force attack on the key somewhat more efficiently than they would otherwise. Found by Jan Jancar using ECTester. Bug introduced in 1.11.20, fixed in 2.9.0
    last seen2020-03-18
    modified2019-01-28
    plugin id121407
    published2019-01-28
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/121407
    titleFreeBSD : botan2 -- Side channel during ECC key generation (d8e7e854-17fa-11e9-bef6-6805ca2fa271)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2020 Jacques Vidrine and contributors
    #
    # Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
    # HTML, PDF, PostScript, RTF and so forth) with or without modification,
    # are permitted provided that the following conditions are met:
    # 1. Redistributions of source code (VuXML) must retain the above
    #    copyright notice, this list of conditions and the following
    #    disclaimer as the first lines of this file unmodified.
    # 2. Redistributions in compiled form (transformed to other DTDs,
    #    published online in any format, converted to PDF, PostScript,
    #    RTF and other formats) must reproduce the above copyright
    #    notice, this list of conditions and the following disclaimer
    #    in the documentation and/or other materials provided with the
    #    distribution.
    # 
    # THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
    # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
    # BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
    # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
    # OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
    # BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
    # WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
    # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
    # EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(121407);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/20");
    
      script_cve_id("CVE-2018-20187");
    
      script_name(english:"FreeBSD : botan2 -- Side channel during ECC key generation (d8e7e854-17fa-11e9-bef6-6805ca2fa271)");
      script_summary(english:"Checks for updated package in pkg_info output");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote FreeBSD host is missing a security-related update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "botan2 developers reports :
    
    A timing side channel during ECC key generation could leak information
    about the high bits of the secret scalar. Such information allows an
    attacker to perform a brute-force attack on the key somewhat more
    efficiently than they would otherwise. Found by Jan Jancar using
    ECTester.
    
    Bug introduced in 1.11.20, fixed in 2.9.0"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://botan.randombit.net/security.html#id1"
      );
      # https://vuxml.freebsd.org/freebsd/d8e7e854-17fa-11e9-bef6-6805ca2fa271.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?05018625"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/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:H/PR:N/UI:N/S:U/C:H/I:N/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:freebsd:freebsd:botan2");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/17");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/01/27");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/01/28");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"FreeBSD Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("freebsd_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
    if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    
    if (pkg_test(save_report:TRUE, pkg:"botan2<2.9.0")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");