Vulnerabilities > CVE-2009-2410 - Improper Authentication vulnerability in Fedorahosted Sssd 0.4.1

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
fedorahosted
CWE-287
nessus

Summary

The local_handler_callback function in server/responder/pam/pam_LOCAL_domain.c in sssd 0.4.1 does not properly handle blank-password accounts in the SSSD BE database, which allows context-dependent attackers to obtain access by sending the account's username, in conjunction with an arbitrary password, over an ssh connection.

Vulnerable Configurations

Part Description Count
Application
Fedorahosted
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 familyFedora Local Security Checks
NASL idFEDORA_2009-8101.NASL
descriptionIf a user was added to the SSSD BE database without setting a password, the user could ssh to the SSSD configured client and enter any password to gain access. This update resolves this issue so users with no password set are no longer able to login. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora 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 id40425
published2009-07-30
reporterThis script is Copyright (C) 2009-2019 Tenable Network Security, Inc.
sourcehttps://www.tenable.com/plugins/nessus/40425
titleFedora 11 : sssd-0.4.1-3.fc11 (2009-8101)
code
#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory 2009-8101.
#

include("compat.inc");

if (description)
{
  script_id(40425);
  script_version ("1.13");
  script_cvs_date("Date: 2019/08/02 13:32:30");

  script_cve_id("CVE-2009-2410");
  script_xref(name:"FEDORA", value:"2009-8101");

  script_name(english:"Fedora 11 : sssd-0.4.1-3.fc11 (2009-8101)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"If a user was added to the SSSD BE database without setting a
password, the user could ssh to the SSSD configured client and enter
any password to gain access. This update resolves this issue so users
with no password set are no longer able to login.

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora 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://bugzilla.redhat.com/show_bug.cgi?id=514057"
  );
  # https://lists.fedoraproject.org/pipermail/package-announce/2009-July/027165.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?a058b48b"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected sssd package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_cwe_id(287);

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:sssd");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:11");

  script_set_attribute(attribute:"patch_publication_date", value:"2009/07/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2009/07/30");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2009-2019 Tenable Network Security, Inc.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


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

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! ereg(pattern:"^11([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 11.x", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) 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, "Fedora", cpu);

flag = 0;
if (rpm_check(release:"FC11", reference:"sssd-0.4.1-3.fc11")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "sssd");
}

Seebug

bulletinFamilyexploit
descriptionBugraq ID: 35868 CVE ID:CVE-2009-2410 Fedora是一款基于linux内核的发行版本。 Fedora SSSD存在验证绕过问题,远程攻击者可以利用漏洞获得对目标系统的未授权访问。 如果用户增加到SSSD BE数据库,但没有设置密码,那么这个用户就可以通过SSH连接配置SSSD客户端机器,并无需任何密码即可访问。 RedHat SSSD 0.4.1-2 RedHat Fedora 11 厂商解决方案 用户可参考如下安全公告获得补丁信息: https://bugzilla.redhat.com/show_bug.cgi?id=514057
idSSV:11936
last seen2017-11-19
modified2009-07-30
published2009-07-30
reporterRoot
titleFedora SSSD BE数据库无密码认证绕过漏洞