Vulnerabilities > CVE-2018-19974 - Use of Uninitialized Resource vulnerability in Virustotal Yara 3.8.1

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
NONE
Availability impact
NONE
local
low complexity
virustotal
CWE-908
nessus

Summary

In YARA 3.8.1, bytecode in a specially crafted compiled rule can read uninitialized data from VM scratch memory in libyara/exec.c. This can allow attackers to discover addresses in the real stack (not the YARA virtual stack).

Vulnerable Configurations

Part Description Count
Application
Virustotal
1

Common Weakness Enumeration (CWE)

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2019-A00B4760A0.NASL
    descriptionbugfix bump to 3.10.0 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 id129637
    published2019-10-07
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/129637
    titleFedora 30 : yara (2019-a00b4760a0)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2019-a00b4760a0.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(129637);
      script_version("1.2");
      script_cvs_date("Date: 2019/12/20");
    
      script_cve_id("CVE-2018-19974", "CVE-2018-19975", "CVE-2018-19976");
      script_xref(name:"FEDORA", value:"2019-a00b4760a0");
    
      script_name(english:"Fedora 30 : yara (2019-a00b4760a0)");
      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:
    "bugfix bump to 3.10.0
    
    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-a00b4760a0"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected yara package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/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:L/AC:L/PR:N/UI:R/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:yara");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/17");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/10/06");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/10/07");
      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:"yara-3.10.0-2.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, "yara");
    }
    
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2019-C3627A0E7A.NASL
    descriptionupdate to the bugfix release 3.9.0 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 id124536
    published2019-05-02
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/124536
    titleFedora 30 : python-yara / yara (2019-c3627a0e7a)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Fedora Security Advisory FEDORA-2019-c3627a0e7a.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(124536);
      script_version("1.3");
      script_cvs_date("Date: 2020/01/21");
    
      script_cve_id("CVE-2018-19974");
      script_xref(name:"FEDORA", value:"2019-c3627a0e7a");
    
      script_name(english:"Fedora 30 : python-yara / yara (2019-c3627a0e7a)");
      script_summary(english:"Checks rpm output for the updated packages.");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Fedora host is missing one or more security updates."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "update to the bugfix release 3.9.0
    
    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-c3627a0e7a"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected python-yara and / or yara packages."
      );
      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:L/AC:L/PR:N/UI:R/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:python-yara");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:yara");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/17");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/04/10");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/02");
      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:"^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:"python-yara-3.9.0-2.fc30")) flag++;
    if (rpm_check(release:"FC30", reference:"yara-3.9.0-1.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, "python-yara / yara");
    }