Vulnerabilities > CVE-2011-1561 - Improper Authentication vulnerability in IBM AIX 6.1

047910
CVSS 6.8 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
ibm
CWE-287
nessus
NVD
Published: 2011-04-05
Updated: 2011-04-05

Summary

The LDAP login feature in bos.rte.security 6.1.6.4 in IBM AIX 6.1, when ldap_auth is enabled in ldap.cfg, allows remote attackers to bypass authentication via a login attempt with an arbitrary password.

Vulnerable Configurations

Part Description Count
OS
Ibm
1

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 familyAIX Local Security Checks
    NASL idAIX_IZ97416.NASL
    descriptionAfter installing bos.rte.security 6.1.6.4 fileset, an LDAP user will be able to log in with an incorrect password. This occurs only when authtype is set to ldap_auth in the /etc/security/ldap/ldap.cfg file. Non-LDAP users can also log in with incorrect passwords if the local users have their SYSTEM attribute in the /etc/security/user file is set to SYSTEM =
    last seen2020-06-01
    modified2020-06-02
    plugin id63826
    published2013-01-24
    reporterThis script is Copyright (C) 2013-2019 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/63826
    titleAIX 6.1 TL 6 : ldapauth (IZ97416)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The text in the description was extracted from AIX Security
# Advisory ldapauth_advisory.asc.
#

include("compat.inc");

if (description)
{
  script_id(63826);
  script_version("1.3");
  script_cvs_date("Date: 2019/09/16 14:13:03");

  script_cve_id("CVE-2011-1561");

  script_name(english:"AIX 6.1 TL 6 : ldapauth (IZ97416)");
  script_summary(english:"Check for APAR IZ97416");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote AIX host is missing a security patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"After installing bos.rte.security 6.1.6.4 fileset, an LDAP user will
be able to log in with an incorrect password. This occurs only when
authtype is set to ldap_auth in the /etc/security/ldap/ldap.cfg file.
Non-LDAP users can also log in with incorrect passwords if the local
users have their SYSTEM attribute in the /etc/security/user file is
set to SYSTEM = 'LDAP', or the default stanza is set to SYSTEM =
'LDAP' and local users do not have SYSTEM set in their own stanza. If
local users don't have LDAP in their SYSTEM attribute, then they will
not be affected."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://aix.software.ibm.com/aix/efixes/security/ldapauth_advisory.asc"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Install the appropriate interim fix."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:ibm:aix:6.1");

  script_set_attribute(attribute:"vuln_publication_date", value:"2011/03/31");
  script_set_attribute(attribute:"patch_publication_date", value:"2011/03/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2013/01/24");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2013-2019 Tenable Network Security, Inc.");
  script_family(english:"AIX Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/AIX/lslpp", "Host/local_checks_enabled", "Host/AIX/version");

  exit(0);
}



include("audit.inc");
include("global_settings.inc");
include("aix.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if ( ! get_kb_item("Host/AIX/version") ) audit(AUDIT_OS_NOT, "AIX");
if ( ! get_kb_item("Host/AIX/lslpp") ) audit(AUDIT_PACKAGE_LIST_MISSING);

if ( get_kb_item("Host/AIX/emgr_failure" ) ) exit(0, "This iFix check is disabled because : "+get_kb_item("Host/AIX/emgr_failure") );

flag = 0;

if (aix_check_ifix(release:"6.1", ml:"06", patch:"IZ97416s04", package:"bos.rte.security", minfilesetver:"6.1.6.4", maxfilesetver:"6.1.6.4") < 0) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:aix_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
  • NASL familyAIX Local Security Checks
    NASL idAIX_U833130.NASL
    descriptionThe remote host is missing AIX PTF U833130, which is related to the security of the package bos.rte.security. After installing bos.rte.security 6.1.6.4 fileset, an LDAP user will be able to log in with an incorrect password. This occurs only when authtype is set to ldap_auth in the /etc/security/ldap/ldap.cfg file. Non-LDAP users can also log in with incorrect passwords if the local users have their SYSTEM attribute in the /etc/security/user file is set to SYSTEM =
    last seen2020-06-01
    modified2020-06-02
    plugin id54341
    published2011-05-19
    reporterThis script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/54341
    titleAIX 6.1 TL 6 : bos.rte.security (U833130)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were extracted
# from AIX Security PTF U833130. The text itself is copyright (C)
# International Business Machines Corp.
#

include("compat.inc");

if (description)
{
  script_id(54341);
  script_version ("1.6");
  script_cvs_date("Date: 2019/09/16 14:13:03");

  script_cve_id("CVE-2011-1561");
  script_bugtraq_id(47125);

  script_name(english:"AIX 6.1 TL 6 : bos.rte.security (U833130)");
  script_summary(english:"Check for PTF U833130");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote AIX host is missing a vendor-supplied security patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"The remote host is missing AIX PTF U833130, which is related to the
security of the package bos.rte.security.

After installing bos.rte.security 6.1.6.4 fileset, an LDAP user will
be able to log in with an incorrect password. This occurs only when
authtype is set to ldap_auth in the /etc/security/ldap/ldap.cfg file.
Non-LDAP users can also log in with incorrect passwords if the local
users have their SYSTEM attribute in the /etc/security/user file is
set to SYSTEM = 'LDAP', or the default stanza is set to SYSTEM =
'LDAP' and local users do not have SYSTEM set in their own stanza. If
local users don't have LDAP in their SYSTEM attribute, then they will
not be affected."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www-01.ibm.com/support/docview.wss?uid=isg1IZ97416"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Install the appropriate missing security-related fix."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/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:"cpe:/o:ibm:aix:6.1");

  script_set_attribute(attribute:"vuln_publication_date", value:"2011/03/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2011/03/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/05/19");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"AIX Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AIX/oslevel", "Host/AIX/version", "Host/AIX/lslpp");

  exit(0);
}



include("audit.inc");
include("global_settings.inc");
include("aix.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if ( ! get_kb_item("Host/AIX/version") ) audit(AUDIT_OS_NOT, "AIX");
if ( ! get_kb_item("Host/AIX/lslpp") ) audit(AUDIT_PACKAGE_LIST_MISSING);

flag = 0;

if ( aix_check_patch(ml:"610006", patch:"U833130", package:"bos.rte.security.6.1.6.15") < 0 ) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:aix_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");

References