Vulnerabilities > CVE-2017-16672 - Missing Release of Resource after Effective Lifetime vulnerability in Digium Asterisk

047910
CVSS 5.9 - MEDIUM
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
high complexity
digium
CWE-772
nessus

Summary

An issue was discovered in Asterisk Open Source 13 before 13.18.1, 14 before 14.7.1, and 15 before 15.1.1 and Certified Asterisk 13.13 before 13.13-cert7. A memory leak occurs when an Asterisk pjsip session object is created and that call gets rejected before the session itself is fully established. When this happens the session object never gets destroyed. Eventually Asterisk can run out of memory and crash.

Vulnerable Configurations

Part Description Count
Application
Digium
154

Common Attack Pattern Enumeration and Classification (CAPEC)

  • HTTP DoS
    An attacker performs flooding at the HTTP level to bring down only a particular web application rather than anything listening on a TCP/IP connection. This denial of service attack requires substantially fewer packets to be sent which makes DoS harder to detect. This is an equivalent of SYN flood in HTTP. The idea is to keep the HTTP session alive indefinitely and then repeat that hundreds of times. This attack targets resource depletion weaknesses in web server software. The web server will wait to attacker's responses on the initiated HTTP sessions while the connection threads are being exhausted.

Nessus

  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4076.NASL
    descriptionMultiple vulnerabilities have been discovered in Asterisk, an open source PBX and telephony toolkit, which may result in denial of service, information disclosure and potentially the execution of arbitrary code.
    last seen2020-06-01
    modified2020-06-02
    plugin id105498
    published2018-01-02
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105498
    titleDebian DSA-4076-1 : asterisk - security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Debian Security Advisory DSA-4076. The text 
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(105498);
      script_version("3.5");
      script_cvs_date("Date: 2019/04/05 23:25:05");
    
      script_cve_id("CVE-2017-16671", "CVE-2017-16672", "CVE-2017-17090", "CVE-2017-17664");
      script_xref(name:"DSA", value:"4076");
    
      script_name(english:"Debian DSA-4076-1 : asterisk - 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-related update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "Multiple vulnerabilities have been discovered in Asterisk, an open
    source PBX and telephony toolkit, which may result in denial of
    service, information disclosure and potentially the execution of
    arbitrary code."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/source-package/asterisk"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/jessie/asterisk"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/stretch/asterisk"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://www.debian.org/security/2017/dsa-4076"
      );
      script_set_attribute(
        attribute:"solution", 
        value:
    "Upgrade the asterisk packages.
    
    For the oldstable distribution (jessie), these problems have been
    fixed in version 1:11.13.1~dfsg-2+deb8u5.
    
    For the stable distribution (stretch), these problems have been fixed
    in version 1:13.14.1~dfsg-2+deb9u3."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2017/12/30");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/01/02");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2018-2019 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:"asterisk", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-config", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-dahdi", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-dbg", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-dev", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-doc", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-mobile", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-modules", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-mp3", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-mysql", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-ooh323", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-voicemail", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-voicemail-imapstorage", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-voicemail-odbcstorage", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"8.0", prefix:"asterisk-vpb", reference:"1:11.13.1~dfsg-2+deb8u5")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-config", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-dahdi", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-dev", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-doc", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-mobile", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-modules", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-mp3", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-mysql", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-ooh323", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-voicemail", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-voicemail-imapstorage", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-voicemail-odbcstorage", reference:"1:13.14.1~dfsg-2+deb9u3")) flag++;
    if (deb_check(release:"9.0", prefix:"asterisk-vpb", reference:"1:13.14.1~dfsg-2+deb9u3")) 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");
    
  • NASL familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201811-11.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201811-11 (Asterisk: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Asterisk. Please review the referenced CVE identifiers for details. Impact : A remote attacker could cause a Denial of Service condition or conduct information gathering. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id119131
    published2018-11-26
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/119131
    titleGLSA-201811-11 : Asterisk: Multiple vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Gentoo Linux Security Advisory GLSA 201811-11.
    #
    # The advisory text is Copyright (C) 2001-2018 Gentoo Foundation, Inc.
    # and licensed under the Creative Commons - Attribution / Share Alike 
    # license. See http://creativecommons.org/licenses/by-sa/3.0/
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(119131);
      script_version("1.1");
      script_cvs_date("Date: 2018/11/26 11:02:12");
    
      script_cve_id("CVE-2017-16671", "CVE-2017-16672", "CVE-2017-17850", "CVE-2018-12227", "CVE-2018-17281");
      script_xref(name:"GLSA", value:"201811-11");
    
      script_name(english:"GLSA-201811-11 : Asterisk: Multiple vulnerabilities");
      script_summary(english:"Checks for updated package(s) in /var/db/pkg");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:
    "The remote Gentoo host is missing one or more security-related
    patches."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "The remote host is affected by the vulnerability described in GLSA-201811-11
    (Asterisk: Multiple vulnerabilities)
    
        Multiple vulnerabilities have been discovered in Asterisk. Please review
          the referenced CVE identifiers for details.
      
    Impact :
    
        A remote attacker could cause a Denial of Service condition or conduct
          information gathering.
      
    Workaround :
    
        There is no known workaround at this time."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security.gentoo.org/glsa/201811-11"
      );
      script_set_attribute(
        attribute:"solution", 
        value:
    "All Asterisk users should upgrade to the latest version:
          # emerge --sync
          # emerge --ask --oneshot --verbose '>=net-misc/asterisk-13.23.1'"
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:asterisk");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2018/11/24");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/11/26");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Gentoo Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/Gentoo/release", "Host/Gentoo/qpkg-list");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("global_settings.inc");
    include("qpkg.inc");
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/Gentoo/release")) audit(AUDIT_OS_NOT, "Gentoo");
    if (!get_kb_item("Host/Gentoo/qpkg-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    
    if (qpkg_check(package:"net-misc/asterisk", unaffected:make_list("ge 13.23.1"), vulnerable:make_list("lt 13.23.1"))) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:qpkg_report_get());
      else security_warning(0);
      exit(0);
    }
    else
    {
      tested = qpkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "Asterisk");
    }
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_BE261737C53511E78DA5001999F8D30B.NASL
    descriptionThe Asterisk project reports : A memory leak occurs when an Asterisk pjsip session object is created and that call gets rejected before the session itself is fully established. When this happens the session object never gets destroyed. This then leads to file descriptors and RTP ports being leaked as well.
    last seen2020-06-01
    modified2020-06-02
    plugin id104491
    published2017-11-10
    reporterThis script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/104491
    titleFreeBSD : asterisk -- Memory/File Descriptor/RTP leak in pjsip session resource (be261737-c535-11e7-8da5-001999f8d30b)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2018 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(104491);
      script_version("3.4");
      script_cvs_date("Date: 2018/11/10 11:49:46");
    
      script_cve_id("CVE-2017-16672");
    
      script_name(english:"FreeBSD : asterisk -- Memory/File Descriptor/RTP leak in pjsip session resource (be261737-c535-11e7-8da5-001999f8d30b)");
      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:
    "The Asterisk project reports :
    
    A memory leak occurs when an Asterisk pjsip session object is created
    and that call gets rejected before the session itself is fully
    established. When this happens the session object never gets
    destroyed. This then leads to file descriptors and RTP ports being
    leaked as well."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://downloads.asterisk.org/pub/security/AST-2017-011.html"
      );
      # https://vuxml.freebsd.org/freebsd/be261737-c535-11e7-8da5-001999f8d30b.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?fb0efab9"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
      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_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:asterisk13");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2017/10/15");
      script_set_attribute(attribute:"patch_publication_date", value:"2017/11/09");
      script_set_attribute(attribute:"plugin_publication_date", value:"2017/11/10");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2017-2018 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:"asterisk13>=13.5.0<13.18.1")) 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");
    
  • NASL familyMisc.
    NASL idASTERISK_AST_2017_009-011.NASL
    descriptionAccording to its SIP banner, the version of Asterisk running on the remote host is 13.x prior to 13.18.1, 14.x prior to 14.7.1, 15.x prior to 15.1.1, or 13.13 prior to 13.13-cert7. It is therefore, affected by multiple vulnerabilities as described in AST-2017-009, AST-2017-010, and AST-2017-011. Also note that Nessus has not tested for these issues but has instead relied only on the application
    last seen2020-06-01
    modified2020-06-02
    plugin id104658
    published2017-11-17
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/104658
    titleAsterisk 13.x < 13.18.1 / 14.x < 14.7.1 / 15.x < 15.1.1 / 13.13 < 13.13-cert7 Multiple Vulnerabilities (AST-2017-009 - AST-2017-011)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(104658);
      script_version("1.6");
      script_cvs_date("Date: 2019/11/12");
    
      script_cve_id("CVE-2017-16671", "CVE-2017-16672");
      script_bugtraq_id(101759, 101760, 101765);
    
      script_name(english:"Asterisk 13.x < 13.18.1 / 14.x < 14.7.1 / 15.x < 15.1.1 / 13.13 < 13.13-cert7 Multiple Vulnerabilities (AST-2017-009 - AST-2017-011)");
      script_summary(english:"Checks the version in the SIP banner.");
    
      script_set_attribute(attribute:"synopsis", value:
    "A telephony application running on the remote host is affected by 
    multiple vulnerabilities.");
      script_set_attribute(attribute:"description", value:
    "According to its SIP banner, the version of Asterisk running on the
    remote host is 13.x prior to 13.18.1, 14.x prior to 14.7.1, 15.x prior
    to 15.1.1, or 13.13 prior to 13.13-cert7. It is therefore, affected by
    multiple vulnerabilities as described in AST-2017-009, AST-2017-010,
    and AST-2017-011.
    
    Also note that Nessus has not tested for these issues but has instead
    relied only on the application's self-reported version number.");
      script_set_attribute(attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2017-009.html");
      script_set_attribute(attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2017-010.html");
      script_set_attribute(attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2017-011.html");
      script_set_attribute(attribute:"solution", value:
    "Upgrade to Asterisk version 13.18.1 / 14.7.1 / 15.1.1 / 13.13-cert7 or later.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
      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:L/UI:N/S:U/C:H/I:H/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-2017-16671");
    
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"false");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2017/10/03");
      script_set_attribute(attribute:"patch_publication_date", value:"2017/11/08");
      script_set_attribute(attribute:"plugin_publication_date", value:"2017/11/17");
    
      script_set_attribute(attribute:"potential_vulnerability", value:"true");
      script_set_attribute(attribute:"plugin_type", value:"remote");
      script_set_attribute(attribute:"cpe", value:"cpe:/a:digium:asterisk");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"Misc.");
    
      script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
    
      script_dependencies("asterisk_detection.nasl");
      script_require_keys("asterisk/sip_detected", "Settings/ParanoidReport");
    
      exit(0);
    }
    
    include("audit.inc");
    include("global_settings.inc");
    include("misc_func.inc");
    
    get_kb_item_or_exit("asterisk/sip_detected");
    
    asterisk_kbs = get_kb_list_or_exit("sip/asterisk/*/version");
    
    if (report_paranoia < 2) audit(AUDIT_PARANOID);
    
    is_vuln = FALSE;
    not_vuln_installs = make_list();
    errors = make_list();
    
    foreach kb_name (keys(asterisk_kbs))
    {
      vulnerable = 0;
    
      matches = pregmatch(pattern:"/(udp|tcp)/([0-9]+)/version", string:kb_name);
      if (isnull(matches))
      {
        errors = make_list(errors, "Unexpected error parsing port number from '"+kb_name+"'.");
        continue;
      }
    
      proto = matches[1];
      port  = matches[2];
      version = asterisk_kbs[kb_name];
    
      if (version == 'unknown')
      {
        errors = make_list(errors, "Unable to obtain version of installation on " + proto + "/" + port + ".");
        continue;
      }
    
      banner = get_kb_item("sip/asterisk/" + proto + "/" + port + "/source");
      if (!banner)
      {
        # We have version but banner is missing;
        # log error and use in version-check though.
        errors = make_list(errors, "KB item 'sip/asterisk/" + proto + "/" + port + "/source' is missing.");
        banner = 'unknown';
      }
    
      if (version =~ "^13([^0-9])" && "cert" >!< tolower(version))
      {
        fixed = "13.18.1";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
      else if (version =~ "^14([^0-9])" && "cert" >!< tolower(version))
      {
        fixed = "14.7.1";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
      else if (version =~ "^15([^0-9])" && "cert" >!< tolower(version))
      {
        fixed = "15.1.1";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
      else if (version =~ "^13\.13([^0-9])" && "cert" >< tolower(version))
      {
        fixed = "13.13-cert7";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
    
      if (vulnerable < 0)
      {
        is_vuln = TRUE;
        report =
            '\n  Version source    : ' + banner +
            '\n  Installed version : ' + version +
            '\n  Fixed version     : ' + fixed +
            '\n';
          security_report_v4(severity:SECURITY_WARNING, port:port, proto:proto, extra:report);
      }
      else not_vuln_installs = make_list(not_vuln_installs, version + " on port " + proto + "/" + port);
    }
    
    if (max_index(errors))
    {
      if (max_index(errors) == 1) errmsg = errors[0];
      else errmsg = 'Errors were encountered verifying installations : \n  ' + join(errors, sep:'\n  ');
    
      exit(1, errmsg);
    }
    else
    {
      installs = max_index(not_vuln_installs);
      if (installs == 0)
      {
        if (is_vuln) exit(0);
        else audit(AUDIT_NOT_INST, "Asterisk");
      }
      else audit(AUDIT_INST_VER_NOT_VULN, "Asterisk", not_vuln_installs);
    }