Vulnerabilities > CVE-2009-3232 - Improper Authentication vulnerability in Canonical Ubuntu Linux 8.10/9.04

047910
CVSS 0.0 - NONE
Attack vector
UNKNOWN
Attack complexity
UNKNOWN
Privileges required
UNKNOWN
Confidentiality impact
UNKNOWN
Integrity impact
UNKNOWN
Availability impact
UNKNOWN

Summary

pam-auth-update for PAM, as used in Ubuntu 8.10 and 9.4, and Debian GNU/Linux, does not properly handle an "empty selection" for system authentication modules in certain rare configurations, which causes any attempt to be successful and allows remote attackers to bypass authentication.

Vulnerable Configurations

Part Description Count
OS
Canonical
2

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Nessus

  • NASL familyGain a shell remotely
    NASL idACCOUNT_ROOT_RANDPW.NASL
    descriptionNessus was able to login to the remote host as
    last seen2020-06-01
    modified2020-06-02
    plugin id40987
    published2009-09-15
    reporterThis script is Copyright (C) 2009-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/40987
    titleRandom password for 'root' account
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    
    include("compat.inc");
    
    
    if (description)
    {
      script_id(40987);
      script_version("1.17");
      script_cvs_date("Date: 2018/11/15 20:50:22");
    
      script_cve_id("CVE-2009-3232");
      script_bugtraq_id(36306);
      script_xref(name:"Secunia", value:"36620");
    
      script_name(english:"Random password for 'root' account");
      script_summary(english:"Tries to SSH as root with a random password.");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote system has an authentication bypass vulnerability."
      );
      script_set_attribute(attribute:"description", value:
    "Nessus was able to login to the remote host as 'root' via SSH with a
    random password.
    
    A remote attacker can exploit this to gain access to the affected
    host, possibly at an administrative level.
    
    This may be due to a known issue with some versions of Ubuntu's
    libpam-runtime package when used in a non-default manner, although
    Nessus has not tried to verify the underlying cause.");
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.launchpad.net/ubuntu/+source/pam/+bug/410171"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://usn.ubuntu.com/828-1/"
      );
      script_set_attribute(attribute:"solution", value:
    "If the remote host is running Ubuntu, upgrade to libpam-runtime
    1.0.1-4ubuntu5.6 / 1.0.1-9ubuntu1.1 or later.
    
    Otherwise, make sure the root account is secured with a strong
    password, and SSH is configured to require authentication.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/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:L/PR:N/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:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"false");
      script_cwe_id(287);
    
      # when this issue was posted to the Ubuntu bug tracker
      script_set_attribute(attribute:"vuln_publication_date", value:"2009/08/07");
      script_set_attribute(attribute:"plugin_publication_date", value:"2009/09/15");
    
      script_set_attribute(attribute:"plugin_type", value:"remote");
      script_set_attribute(attribute:"default_account", value:"true");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"Gain a shell remotely");
    
      script_copyright(english:"This script is Copyright (C) 2009-2018 Tenable Network Security, Inc.");
    
      script_dependencie("find_service1.nasl", "ssh_detect.nasl", "account_check.nasl");
      script_require_ports("Services/ssh", 22);
      script_exclude_keys("global_settings/supplied_logins_only");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("global_settings.inc");
    include("default_account.inc");
    
    if (supplied_logins_only) audit(AUDIT_SUPPLIED_LOGINS_ONLY);
    
    port = check_account(login:rand_str(length:8), password:rand_str(length:8));
    if ( port ) exit(0, "Any login/password pair is accepted?");
    
    account = 'root';
    password1 = string(SCRIPT_NAME, unixtime());
    password2 = string(SCRIPT_NAME, rand());
    
    affected = FALSE;
    ssh_ports = get_service_port_list(svc: "ssh", default:22);
    foreach port (ssh_ports)
    {
      port = check_account(login:account, password:password1, port:port, svc:"ssh");
      if (port)
      {
        affected = TRUE;
        if (report_paranoia == 2)
        {
          security_report_v4(port:port, severity:SECURITY_HOLE, extra:default_account_report());
          exit(0);
        }
        else
        {
          # If paranoia isn't high, try to login again using a different password, just to
          # make sure the system really will let us login with any password
          port = check_account(login:account, password:password2, port:port, svc:"ssh");
          if (port)
          {
            affected = TRUE;
            security_report_v4(port:port, severity:SECURITY_HOLE, extra:default_account_report());
          }
        }
      }
    }
    if(affected) exit(0);
    
    telnet_ports = get_service_port_list(svc: "telnet", default:23);
    foreach port (telnet_ports)
    {
      port = check_account(login:account, password:password1, port:port, svc:"telnet");
      if (port)
      {
        affected = TRUE;
        if (report_paranoia == 2)
        {
          security_report_v4(port:port, severity:SECURITY_HOLE, extra:default_account_report());
          exit(0);
        }
        else
        {
          # If paranoia isn't high, try to login again using a different password, just to
          # make sure the system really will let us login with any password
          port = check_account(login:account, password:password2, port:port, svc:"telnet");
          if (port)
          {
            affected = TRUE;
            security_report_v4(port:port, severity:SECURITY_HOLE, extra:default_account_report());
          }
        }
      }
    }
    if(!affected) audit(AUDIT_HOST_NOT, "affected");
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-828-1.NASL
    descriptionRussell Senior discovered that the system authentication module selection mechanism for PAM did not safely handle an empty selection. If an administrator had specifically removed the default list of modules or failed to chose a module when operating debconf in a very unlikely non-default configuration, PAM would allow any authentication attempt, which could lead to remote attackers gaining access to a system with arbitrary privileges. This did not affect default Ubuntu installations. 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 id40906
    published2009-09-09
    reporterUbuntu Security Notice (C) 2009-2019 Canonical, Inc. / NASL script (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/40906
    titleUbuntu 8.10 / 9.04 : pam vulnerability (USN-828-1)
    code
    #%NASL_MIN_LEVEL 80502
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Ubuntu Security Notice USN-828-1. The text 
    # itself is copyright (C) Canonical, Inc. See 
    # <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
    # trademark of Canonical, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(40906);
      script_version("1.12");
      script_cvs_date("Date: 2019/08/02 13:33:02");
    
      script_cve_id("CVE-2009-3232");
      script_xref(name:"USN", value:"828-1");
    
      script_name(english:"Ubuntu 8.10 / 9.04 : pam vulnerability (USN-828-1)");
      script_summary(english:"Checks dpkg output for updated packages.");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:
    "The remote Ubuntu host is missing one or more security-related
    patches."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "Russell Senior discovered that the system authentication module
    selection mechanism for PAM did not safely handle an empty selection.
    If an administrator had specifically removed the default list of
    modules or failed to chose a module when operating debconf in a very
    unlikely non-default configuration, PAM would allow any authentication
    attempt, which could lead to remote attackers gaining access to a
    system with arbitrary privileges. This did not affect default Ubuntu
    installations.
    
    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."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://usn.ubuntu.com/828-1/"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected packages.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
      script_cwe_id(287);
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-cracklib");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-doc");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-modules");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-runtime");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g-dev");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:8.10");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:9.04");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2009/09/08");
      script_set_attribute(attribute:"plugin_publication_date", value:"2009/09/09");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"Ubuntu Security Notice (C) 2009-2019 Canonical, Inc. / NASL script (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Ubuntu Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("ubuntu.inc");
    include("misc_func.inc");
    
    if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    release = get_kb_item("Host/Ubuntu/release");
    if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
    release = chomp(release);
    if (! ereg(pattern:"^(8\.10|9\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 8.10 / 9.04", "Ubuntu " + release);
    if ( ! get_kb_item("Host/Debian/dpkg-l") ) 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, "Ubuntu", cpu);
    
    flag = 0;
    
    if (ubuntu_check(osver:"8.10", pkgname:"libpam-cracklib", pkgver:"1.0.1-4ubuntu5.6")) flag++;
    if (ubuntu_check(osver:"8.10", pkgname:"libpam-doc", pkgver:"1.0.1-4ubuntu5.6")) flag++;
    if (ubuntu_check(osver:"8.10", pkgname:"libpam-modules", pkgver:"1.0.1-4ubuntu5.6")) flag++;
    if (ubuntu_check(osver:"8.10", pkgname:"libpam-runtime", pkgver:"1.0.1-4ubuntu5.6")) flag++;
    if (ubuntu_check(osver:"8.10", pkgname:"libpam0g", pkgver:"1.0.1-4ubuntu5.6")) flag++;
    if (ubuntu_check(osver:"8.10", pkgname:"libpam0g-dev", pkgver:"1.0.1-4ubuntu5.6")) flag++;
    if (ubuntu_check(osver:"9.04", pkgname:"libpam-cracklib", pkgver:"1.0.1-9ubuntu1.1")) flag++;
    if (ubuntu_check(osver:"9.04", pkgname:"libpam-doc", pkgver:"1.0.1-9ubuntu1.1")) flag++;
    if (ubuntu_check(osver:"9.04", pkgname:"libpam-modules", pkgver:"1.0.1-9ubuntu1.1")) flag++;
    if (ubuntu_check(osver:"9.04", pkgname:"libpam-runtime", pkgver:"1.0.1-9ubuntu1.1")) flag++;
    if (ubuntu_check(osver:"9.04", pkgname:"libpam0g", pkgver:"1.0.1-9ubuntu1.1")) flag++;
    if (ubuntu_check(osver:"9.04", pkgname:"libpam0g-dev", pkgver:"1.0.1-9ubuntu1.1")) flag++;
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_HOLE,
        extra      : ubuntu_report_get()
      );
      exit(0);
    }
    else
    {
      tested = ubuntu_pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libpam-cracklib / libpam-doc / libpam-modules / libpam-runtime / etc");
    }