Vulnerabilities > CVE-2013-6422 - Improper Input Validation vulnerability in multiple products

047910
CVSS 4.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
NONE
network
high complexity
debian
canonical
haxx
CWE-20
nessus

Summary

The GnuTLS backend in libcurl 7.21.4 through 7.33.0, when disabling digital signature verification (CURLOPT_SSL_VERIFYPEER), also disables the CURLOPT_SSL_VERIFYHOST check for CN or SAN host name fields, which makes it easier for remote attackers to spoof servers and conduct man-in-the-middle (MITM) attacks.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyWeb Servers
    NASL idHPSMH_7_4.NASL
    descriptionAccording to the web server
    last seen2020-06-01
    modified2020-06-02
    plugin id78090
    published2014-10-08
    reporterThis script is Copyright (C) 2014-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/78090
    titleHP System Management Homepage < 7.4 Multiple Vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(78090);
      script_version("1.10");
      script_cvs_date("Date: 2018/11/15 20:50:25");
    
      script_cve_id(
        "CVE-2013-4545",
        "CVE-2013-6420",
        "CVE-2013-6422",
        "CVE-2013-6712",
        "CVE-2014-2640",
        "CVE-2014-2641",
        "CVE-2014-2642"
      );
      script_bugtraq_id(63776, 64018, 64225, 64431, 70206, 70208);
      script_xref(name:"HP", value:"emr_na-c04463322");
      script_xref(name:"CERT", value:"125228");
    
      script_name(english:"HP System Management Homepage < 7.4 Multiple Vulnerabilities");
      script_summary(english:"Checks the banner.");
    
      script_set_attribute(attribute:"synopsis", value:"The remote web server is affected by multiple vulnerabilities.");
      script_set_attribute(attribute:"description", value:
    "According to the web server's banner, the version of HP System
    Management Homepage (SMH) hosted on the remote web server is affected
    by the following vulnerabilities :
    
      - A flaw exists within the included cURL that disables the
        'CURLOPT_SSLVERIFYHOST' check when the setting on
        'CURLOPT_SSL_VERIFYPEER' is disabled. This can allow a
        remote attacker to disable SSL certificate host name
        checks. (CVE-2013-4545)
    
      - A flaw exists in the included PHP 'openssl_x509_parse'
        function due to user input not being properly sanitized.
        Using a specially crafted certificate, a remote attacker
        can exploit this to cause a denial of service or execute
        arbitrary code. (CVE-2013-6420)
    
      - A flaw exists within the included cURL where the
        verification check for the CN and SAN name fields is
        skipped due to the digital signature verification being
        disabled. A remote attacker can exploit this to spoof
        servers or conduct a man-in-the-middle attack.
        (CVE-2013-6422)
    
      - A flaw exists in the scan function within the included
        PHP 'ext/date/lib/parse_iso_intervals.c' script where
        user input is not properly sanitized. This can allow a
        remote attacker to cause a denial of service using a
        heap-based buffer overflow. (CVE-2013-6712)
    
      - An unspecified cross-site scripting flaw exists which
        can allow a remote attacker, using a specially crafted
        request, to execute arbitrary code within the
        browser / server trust relationship. (CVE-2014-2640)
    
      - An unspecified cross-site request forgery vulnerability
        exists. (CVE-2014-2641)
    
      - An unspecified vulnerability exists that can allow
        a remote attacker to conduct clickjacking attacks.
        (CVE-2014-2642)");
      # https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-c04463322
      script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?864fedac");
      script_set_attribute(attribute:"see_also", value:"https://www.securityfocus.com/archive/1/533589/30/0/threaded");
      script_set_attribute(attribute:"solution", value:"Upgrade to HP System Management Homepage 7.4 or later.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
      script_cwe_id(20, 74, 79, 442, 629, 711, 712, 722, 725, 750, 751, 800, 801, 809, 811, 864, 900, 928, 931, 990);
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2013/10/03");
      script_set_attribute(attribute:"patch_publication_date", value:"2014/09/30");
      script_set_attribute(attribute:"plugin_publication_date", value:"2014/10/08");
    
      script_set_attribute(attribute:"cpe", value:"cpe:/a:hp:system_management_homepage");
      script_set_attribute(attribute:"plugin_type", value:"remote");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"Web Servers");
    
      script_copyright(english:"This script is Copyright (C) 2014-2018 Tenable Network Security, Inc.");
    
      script_dependencies("compaq_wbem_detect.nasl", "os_fingerprint.nasl");
      script_require_keys("www/hp_smh");
      script_require_ports("Services/www", 2301, 2381);
    
      exit(0);
    }
    
    include("audit.inc");
    include("global_settings.inc");
    include("misc_func.inc");
    include("http.inc");
    include("webapp_func.inc");
    
    get_kb_item_or_exit("www/hp_smh");
    
    port    = get_http_port(default:2381, embedded:TRUE);
    
    install = get_install_from_kb(appname:'hp_smh', port:port, exit_on_fail:TRUE);
    dir     = install['dir'];
    version = install['ver'];
    prod    = get_kb_item_or_exit("www/"+port+"/hp_smh/variant");
    
    if (version == UNKNOWN_VER) exit(1, 'The version of '+prod+' installed at '+build_url(port:port, qs:dir+"/")+' is unknown.');
    
    # Only Linux and Windows are affected -- HP-UX is not mentioned
    if (report_paranoia < 2)
    {
      os = get_kb_item_or_exit("Host/OS");
      if ("Windows" >!< os && "Linux" >!< os) audit(AUDIT_OS_NOT, "Windows or Linux", os);
    }
    
    # nb: 'version' can have non-numeric characters in it so we'll create
    #     an alternate form and make sure that's safe for use in 'ver_compare()'.
    version_alt = ereg_replace(pattern:"[_-]", replace:".", string:version);
    if (!ereg(pattern:"^[0-9][0-9.]+$", string:version_alt)) exit(1, 'The version of '+prod+' installed at '+build_url(port:port, qs:dir+"/")+' does not look valid ('+version+').');
    
    fixed_version = '7.4';
    if (
      version_alt =~ "^7\.[34]([^0-9]|$)" &&
      ver_compare(ver:version_alt, fix:fixed_version, strict:FALSE) == -1)
    {
      source_line = get_kb_item("www/"+port+"/hp_smh/source");
    
      report = '\n  Product           : ' + prod;
      if (!isnull(source_line))
        report += '\n  Version source    : ' + source_line;
      report +=
        '\n  Installed version : ' + version +
        '\n  Fixed version     : ' + fixed_version + 
        '\n';
    
      security_report_v4(severity:SECURITY_HOLE, port:port, extra:report, xss:TRUE, xsrf:TRUE);
    }
    else audit(AUDIT_LISTEN_NOT_VULN, prod, port, version);
    
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-2058-1.NASL
    descriptionMarc Deslauriers discovered that libcurl incorrectly verified CN and SAN name fields when digital signature verification was disabled in the GnuTLS backend. When libcurl is being used in this uncommon way by specific applications, an attacker could exploit this to perform a man in the middle attack to view sensitive information or alter encrypted communications. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. 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 id71531
    published2013-12-19
    reporterUbuntu Security Notice (C) 2013-2019 Canonical, Inc. / NASL script (C) 2013-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/71531
    titleUbuntu 12.04 LTS / 12.10 / 13.04 / 13.10 : curl vulnerability (USN-2058-1)
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-2824.NASL
    descriptionMarc Deslauriers discovered that curl, a file retrieval tool, would mistakenly skip verifying the CN and SAN name fields when digital signature verification was disabled in the libcurl GnuTLS backend. The default configuration for the curl package is not affected by this issue since the digital signature verification is enabled by default. The oldstable distribution (squeeze) is not affected by this problem.
    last seen2020-03-17
    modified2013-12-20
    plugin id71541
    published2013-12-20
    reporterThis script is Copyright (C) 2013-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/71541
    titleDebian DSA-2824-1 : curl - unchecked tls/ssl certificate host name
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_4E1F4ABC683711E39CDA3C970E169BC2.NASL
    descriptioncURL project reports : libcurl is vulnerable to a case of missing out the checking of the certificate CN or SAN name field when the digital signature verification is turned off. libcurl offers two separate and independent options for verifying a server
    last seen2020-06-01
    modified2020-06-02
    plugin id71530
    published2013-12-19
    reporterThis script is Copyright (C) 2013-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/71530
    titleFreeBSD : cURL library -- cert name check ignore with GnuTLS (4e1f4abc-6837-11e3-9cda-3c970e169bc2)
  • NASL familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201401-14.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201401-14 (cURL: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in cURL. Please review the CVE identifiers referenced below for details. Impact : A remote attacker could entice a user or automated process to connect to a malicious server using cURL, possibly resulting in the remote execution of arbitrary code or a Denial of Service condition. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id72053
    published2014-01-21
    reporterThis script is Copyright (C) 2014-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/72053
    titleGLSA-201401-14 : cURL: Multiple vulnerabilities
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-1172.NASL
    descriptionAccording to the versions of the curl packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities : - cURL and libcurl 7.18.0 through 7.32.0, when built with OpenSSL, disables the certificate CN and SAN name field verification (CURLOPT_SSL_VERIFYHOST) when the digital signature verification (CURLOPT_SSL_VERIFYPEER) is disabled, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.i1/4^CVE-2013-4545i1/4%0 - The GnuTLS backend in libcurl 7.21.4 through 7.33.0, when disabling digital signature verification (CURLOPT_SSL_VERIFYPEER), also disables the CURLOPT_SSL_VERIFYHOST check for CN or SAN host name fields, which makes it easier for remote attackers to spoof servers and conduct man-in-the-middle (MITM) attacks.i1/4^CVE-2013-6422i1/4%0 - cURL and libcurl 7.1 before 7.36.0, when using the OpenSSL, axtls, qsossl or gskit libraries for TLS, recognize a wildcard IP address in the subject
    last seen2020-03-19
    modified2019-04-09
    plugin id123858
    published2019-04-09
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/123858
    titleEulerOS Virtualization 2.5.3 : curl (EulerOS-SA-2019-1172)