Vulnerabilities > CVE-2014-8417 - Permissions, Privileges, and Access Controls vulnerability in Digium Asterisk and Certified Asterisk

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
digium
CWE-264
nessus

Summary

ConfBridge in Asterisk 11.x before 11.14.1, 12.x before 12.7.1, and 13.x before 13.0.1 and Certified Asterisk 11.6 before 11.6-cert8 allows remote authenticated users to (1) gain privileges via vectors related to an external protocol to the CONFBRIDGE dialplan function or (2) execute arbitrary system commands via a crafted ConfbridgeStartRecord AMI action.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.

Nessus

  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_7BFD797C716D11E4B008001999F8D30B.NASL
    descriptionThe Asterisk project reports : AST-2014-014 - High call load may result in hung channels in ConfBridge. AST-2014-017 - Permission escalation through ConfBridge actions/dialplan functions.
    last seen2020-06-01
    modified2020-06-02
    plugin id79401
    published2014-11-24
    reporterThis script is Copyright (C) 2014-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/79401
    titleFreeBSD : asterisk -- Multiple vulnerabilities (7bfd797c-716d-11e4-b008-001999f8d30b)
    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(79401);
      script_version("1.4");
      script_cvs_date("Date: 2018/11/10 11:49:43");
    
      script_cve_id("CVE-2014-8414", "CVE-2014-8417");
    
      script_name(english:"FreeBSD : asterisk -- Multiple vulnerabilities (7bfd797c-716d-11e4-b008-001999f8d30b)");
      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 :
    
    AST-2014-014 - High call load may result in hung channels in
    ConfBridge.
    
    AST-2014-017 - Permission escalation through ConfBridge
    actions/dialplan functions."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"http://downloads.asterisk.org/pub/security/AST-2014-014.html"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"http://downloads.asterisk.org/pub/security/AST-2014-017.html"
      );
      # https://vuxml.freebsd.org/freebsd/7bfd797c-716d-11e4-b008-001999f8d30b.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?8e53008b"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:asterisk11");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2014/11/21");
      script_set_attribute(attribute:"patch_publication_date", value:"2014/11/21");
      script_set_attribute(attribute:"plugin_publication_date", value:"2014/11/24");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2014-2018 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:"asterisk11<11.14.1")) 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 familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201412-51.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201412-51 (Asterisk: Multiple vulnerabilities) Multiple unspecified vulnerabilities have been discovered in Asterisk. Please review the CVE identifiers referenced below for details. Impact : Unauthenticated remote attackers can cause Denial of Service or bypass intended ACL restrictions. Authenticated remote attackers can gain escalated privileges. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id80272
    published2014-12-29
    reporterThis script is Copyright (C) 2014-2015 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/80272
    titleGLSA-201412-51 : 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 201412-51.
    #
    # The advisory text is Copyright (C) 2001-2015 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(80272);
      script_version("$Revision: 1.3 $");
      script_cvs_date("$Date: 2015/04/13 14:33:57 $");
    
      script_cve_id("CVE-2014-8412", "CVE-2014-8414", "CVE-2014-8417", "CVE-2014-8418", "CVE-2014-9374");
      script_bugtraq_id(71218, 71222, 71227, 71228, 71607);
      script_xref(name:"GLSA", value:"201412-51");
    
      script_name(english:"GLSA-201412-51 : 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-201412-51
    (Asterisk: Multiple vulnerabilities)
    
        Multiple unspecified vulnerabilities have been discovered in Asterisk.
          Please review the CVE identifiers referenced below for details.
      
    Impact :
    
        Unauthenticated remote attackers can cause Denial of Service or bypass
          intended ACL restrictions. Authenticated remote attackers can gain
          escalated privileges.
      
    Workaround :
    
        There is no known workaround at this time."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security.gentoo.org/glsa/201412-51"
      );
      script_set_attribute(
        attribute:"solution", 
        value:
    "All asterisk users should upgrade to the latest version:
          # emerge --sync
          # emerge --ask --oneshot --verbose '>=net-misc/asterisk-11.14.2'"
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C");
      script_set_cvss_temporal_vector("CVSS2#E:ND/RL:OF/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"false");
    
      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:"2014/12/28");
      script_set_attribute(attribute:"plugin_publication_date", value:"2014/12/29");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2014-2015 Tenable Network Security, Inc.");
      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 11.14.2"), vulnerable:make_list("lt 11.14.2"))) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_hole(port:0, extra:qpkg_report_get());
      else security_hole(0);
      exit(0);
    }
    else
    {
      tested = qpkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "Asterisk");
    }
    
  • NASL familyMisc.
    NASL idASTERISK_AST_2014_017.NASL
    descriptionAccording to the version in its SIP banner, the version of Asterisk running on the remote host is potentially affected by a privilege escalation vulnerability in the ConfBridge
    last seen2020-06-01
    modified2020-06-02
    plugin id79441
    published2014-11-25
    reporterThis script is Copyright (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/79441
    titleAsterisk ConfBridge 'dialplan' Privilege Escalation (AST-2014-017)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(79441);
      script_version("1.10");
      script_cvs_date("Date: 2019/11/25");
    
      script_cve_id("CVE-2014-8417");
      script_bugtraq_id(71228);
    
      script_name(english:"Asterisk ConfBridge 'dialplan' Privilege Escalation (AST-2014-017)");
      script_summary(english:"Checks version in SIP banner.");
    
      script_set_attribute(attribute:"synopsis", value:
    "A telephony application running on the remote host is affected by a
    privilege escalation vulnerability.");
      script_set_attribute(attribute:"description", value:
    "According to the version in its SIP banner, the version of Asterisk
    running on the remote host is potentially affected by a privilege
    escalation vulnerability in the ConfBridge 'dialplan' function that is
    triggered when executed from an external protocol. This could allow a
    remote, authenticated attacker to escalate privileges. Additionally,
    the 'ConfbridgeStartRecord' AMI action could be leveraged to execute
    arbitrary system commands.
    
    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-2014-017.html");
      script_set_attribute(attribute:"see_also", value:"https://issues.asterisk.org/jira/browse/ASTERISK-24490");
      script_set_attribute(attribute:"solution", value:
    "Upgrade to Asterisk 11.14.1 / 12.7.1 / 13.0.1 / 11.6-cert8 or apply
    the appropriate patch listed in the Asterisk advisory.");
      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_attribute(attribute:"cvss_score_source", value:"CVE-2014-8417");
    
      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:"2014/11/20");
      script_set_attribute(attribute:"patch_publication_date", value:"2014/11/20");
      script_set_attribute(attribute:"plugin_publication_date", value:"2014/11/25");
    
      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) 2014-2019 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 = eregmatch(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 install 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';
      }
    
    
      # Open Source 11.x < 11.14.1
      if (version =~ "^11([^0-9]|$)" && "cert" >!< tolower(version))
      {
        fixed = "11.14.1";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
    
      # Open Source 12.x < 12.7.1
      else if (version =~ "^12([^0-9]|$)" && "cert" >!< tolower(version))
      {
        fixed = "12.7.1";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
    
      # Open Source 13.x < 13.0.1
      else if (version =~ "^13([^0-9]|$)" && "cert" >!< tolower(version))
      {
        fixed = "13.0.1";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
    
      # Asterisk Certified 11.6-certx < 11.6-cert3
      else if (version =~ "^11\.6([^0-9])" && "cert" >< tolower(version))
      {
        fixed = "11.6-cert8";
        vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
      }
    
    
      if (vulnerable < 0)
      {
        is_vuln = TRUE;
        if (report_verbosity > 0)
        {
          report =
            '\n  Version source    : ' + banner +
            '\n  Installed version : ' + version +
            '\n  Fixed version     : ' + fixed + 
            '\n';
          security_warning(port:port, proto:proto, extra:report);
        }
        else security_warning(port:port, proto:proto);
      }
      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 installs : \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);
    }