Vulnerabilities > CVE-2019-18849 - Out-of-bounds Read vulnerability in multiple products

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH

Summary

In tnef before 1.4.18, an attacker may be able to write to the victim's .ssh/authorized_keys file via an e-mail message with a crafted winmail.dat application/ms-tnef attachment, because of a heap-based buffer over-read involving strdup.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Overread Buffers
    An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2019-5F14B810F8.NASL
    descriptiontnef release 1.4.18. ==================== Security release to resolve [CVE-2019-18849](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-20 19-18849) in which it may be possible to attack via a crafted email message extracted via tnef. 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 id131711
    published2019-12-05
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/131711
    titleFedora 30 : tnef (2019-5f14b810f8)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2019-5f14b810f8.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(131711);
      script_version("1.4");
      script_cvs_date("Date: 2019/12/12");
    
      script_cve_id("CVE-2019-0001", "CVE-2019-18849");
      script_xref(name:"FEDORA", value:"2019-5f14b810f8");
    
      script_name(english:"Fedora 30 : tnef (2019-5f14b810f8)");
      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:
    "tnef release 1.4.18. ==================== Security release to resolve
    [CVE-2019-18849](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-20
    19-18849) in which it may be possible to attack via a crafted email
    message extracted via tnef.
    
    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-2019-5f14b810f8"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected tnef package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:H/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-2019-0001");
      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:tnef");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/01/15");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/12/05");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/12/05");
      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:"tnef-1.4.18-1.fc30")) 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, "tnef");
    }
    
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2019-815807C020.NASL
    descriptiontnef release 1.4.18. ==================== Security release to resolve [CVE-2019-18849](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-20 19-18849) in which it may be possible to attack via a crafted email message extracted via tnef. 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 id131712
    published2019-12-05
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/131712
    titleFedora 31 : tnef (2019-815807c020)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2019-815807c020.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(131712);
      script_version("1.4");
      script_cvs_date("Date: 2019/12/12");
    
      script_cve_id("CVE-2019-0001", "CVE-2019-18849");
      script_xref(name:"FEDORA", value:"2019-815807c020");
    
      script_name(english:"Fedora 31 : tnef (2019-815807c020)");
      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:
    "tnef release 1.4.18. ==================== Security release to resolve
    [CVE-2019-18849](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-20
    19-18849) in which it may be possible to attack via a crafted email
    message extracted via tnef.
    
    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-2019-815807c020"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected tnef package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:H/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-2019-0001");
      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:tnef");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/01/15");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/12/05");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/12/05");
      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:"tnef-1.4.18-1.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, "tnef");
    }
    
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-2005.NASL
    descriptionIn tnef, an attacker may be able to write to the victim
    last seen2020-06-01
    modified2020-06-02
    plugin id131430
    published2019-12-03
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/131430
    titleDebian DLA-2005-1 : tnef security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Debian Security Advisory DLA-2005-1. The text
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(131430);
      script_version("1.2");
      script_cvs_date("Date: 2019/12/09");
    
      script_cve_id("CVE-2019-18849");
    
      script_name(english:"Debian DLA-2005-1 : tnef 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:
    "In tnef, an attacker may be able to write to the victim's
    .ssh/authorized_keys file via an e-mail message with a crafted
    winmail.dat application/ms-tnef attachment, because of a heap-based
    buffer over-read involving strdup.
    
    For Debian 8 'Jessie', this problem has been fixed in version
    1.4.9-1+deb8u4.
    
    We recommend that you upgrade your tnef 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/2019/11/msg00035.html"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/jessie/tnef"
      );
      script_set_attribute(attribute:"solution", value:"Upgrade the affected tnef package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:L/AC:L/PR:N/UI:R/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:tnef");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/11/11");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/11/29");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/12/03");
      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:"tnef", reference:"1.4.9-1+deb8u4")) 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");