Vulnerabilities > CVE-2018-1113 - Incorrect Permission Assignment for Critical Resource vulnerability in Redhat products

047910
CVSS 5.3 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
LOW
Integrity impact
LOW
Availability impact
LOW
local
low complexity
redhat
CWE-732
nessus

Summary

setup before version 2.11.4-1.fc28 in Fedora and Red Hat Enterprise Linux added /sbin/nologin and /usr/sbin/nologin to /etc/shells. This violates security assumptions made by pam_shells and some daemons which allow access based on a user's shell being listed in /etc/shells. Under some circumstances, users which had their shell changed to /sbin/nologin could still access the system.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Accessing Functionality Not Properly Constrained by ACLs
    In applications, particularly web applications, access to functionality is mitigated by the authorization framework, whose job it is to map ACLs to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application or can run queries for data that he is otherwise not supposed to.
  • Privilege Abuse
    An adversary is able to exploit features of the target that should be reserved for privileged users or administrators but are exposed to use by lower or non-privileged accounts. Access to sensitive information and functionality must be controlled to ensure that only authorized users are able to access these resources. If access control mechanisms are absent or misconfigured, a user may be able to access resources that are intended only for higher level users. An adversary may be able to exploit this to utilize a less trusted account to gain information and perform activities reserved for more trusted accounts. This attack differs from privilege escalation and other privilege stealing attacks in that the adversary never actually escalates their privileges but instead is able to use a lesser degree of privilege to access resources that should be (but are not) reserved for higher privilege accounts. Likewise, the adversary does not exploit trust or subvert systems - all control functionality is working as configured but the configuration does not adequately protect sensitive resources at an appropriate level.
  • Directory Indexing
    An adversary crafts a request to a target that results in the target listing/indexing the content of a directory as output. One common method of triggering directory contents as output is to construct a request containing a path that terminates in a directory name rather than a file name since many applications are configured to provide a list of the directory's contents when such a request is received. An adversary can use this to explore the directory tree on a target as well as learn the names of files. This can often end up revealing test files, backup files, temporary files, hidden files, configuration files, user accounts, script contents, as well as naming conventions, all of which can be used by an attacker to mount additional attacks.
  • 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.
  • Exploiting Incorrectly Configured Access Control Security Levels
    An attacker exploits a weakness in the configuration of access controls and is able to bypass the intended protection that these measures guard against and thereby obtain unauthorized access to the system or network. Sensitive functionality should always be protected with access controls. However configuring all but the most trivial access control systems can be very complicated and there are many opportunities for mistakes. If an attacker can learn of incorrectly configured access security settings, they may be able to exploit this in an attack. Most commonly, attackers would take advantage of controls that provided too little protection for sensitive activities in order to perform actions that should be denied to them. In some circumstances, an attacker may be able to take advantage of overly restrictive access control policies, initiating denial of services (if an application locks because it unexpectedly failed to be granted access) or causing other legitimate actions to fail due to security. The latter class of attacks, however, is usually less severe and easier to detect than attacks based on inadequate security restrictions. This attack pattern differs from CAPEC 1, "Accessing Functionality Not Properly Constrained by ACLs" in that the latter describes attacks where sensitive functionality lacks access controls, where, in this pattern, the access control is present, but incorrectly configured.

Nessus

  • NASL familyNewStart CGSL Local Security Checks
    NASL idNEWSTART_CGSL_NS-SA-2019-0075_SETUP.NASL
    descriptionThe remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has setup packages installed that are affected by a vulnerability: - Setup in Fedora and Red Hat Enterprise Linux added /sbin/nologin and /usr/sbin/nologin to /etc/shells. This violates security assumptions made by pam_shells and some daemons which allow access based on a user
    last seen2020-06-01
    modified2020-06-02
    plugin id127282
    published2019-08-12
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/127282
    titleNewStart CGSL CORE 5.04 / MAIN 5.04 : setup Vulnerability (NS-SA-2019-0075)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    # The descriptive text and package checks in this plugin were
    # extracted from ZTE advisory NS-SA-2019-0075. The text
    # itself is copyright (C) ZTE, Inc.
    
    include("compat.inc");
    
    if (description)
    {
      script_id(127282);
      script_version("1.2");
      script_cvs_date("Date: 2019/10/17 14:31:04");
    
      script_cve_id("CVE-2018-1113");
    
      script_name(english:"NewStart CGSL CORE 5.04 / MAIN 5.04 : setup Vulnerability (NS-SA-2019-0075)");
    
      script_set_attribute(attribute:"synopsis", value:
    "The remote machine is affected by a vulnerability.");
      script_set_attribute(attribute:"description", value:
    "The remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has setup packages installed that are affected by
    a vulnerability:
    
      - Setup in Fedora and Red Hat Enterprise Linux added
        /sbin/nologin and /usr/sbin/nologin to /etc/shells. This
        violates security assumptions made by pam_shells and
        some daemons which allow access based on a user's shell
        being listed in /etc/shells. Under some circumstances,
        users which had their shell changed to /sbin/nologin
        could still access the system. (CVE-2018-1113)
    
    Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
    number.");
      script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/notice/NS-SA-2019-0075");
      script_set_attribute(attribute:"solution", value:
    "Upgrade the vulnerable CGSL setup packages. Note that updated packages may not be available yet. Please contact ZTE for
    more information.");
      script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-1113");
    
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/07/03");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/07/17");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/12");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"NewStart CGSL Local Security Checks");
    
      script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/ZTE-CGSL/release", "Host/ZTE-CGSL/rpm-list", "Host/cpu");
    
      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/ZTE-CGSL/release");
    if (isnull(release) || release !~ "^CGSL (MAIN|CORE)") audit(AUDIT_OS_NOT, "NewStart Carrier Grade Server Linux");
    
    if (release !~ "CGSL CORE 5.04" &&
        release !~ "CGSL MAIN 5.04")
      audit(AUDIT_OS_NOT, 'NewStart CGSL CORE 5.04 / NewStart CGSL MAIN 5.04');
    
    if (!get_kb_item("Host/ZTE-CGSL/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, "NewStart Carrier Grade Server Linux", cpu);
    
    flag = 0;
    
    pkgs = {
      "CGSL CORE 5.04": [
        "setup-2.8.71-10.el7"
      ],
      "CGSL MAIN 5.04": [
        "setup-2.8.71-10.el7"
      ]
    };
    pkg_list = pkgs[release];
    
    foreach (pkg in pkg_list)
      if (rpm_check(release:"ZTE " + release, reference:pkg)) flag++;
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_WARNING,
        extra      : rpm_report_get()
      );
      exit(0);
    }
    else
    {
      tested = pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "setup");
    }
    
  • NASL familyOracle Linux Local Security Checks
    NASL idORACLELINUX_ELSA-2018-3249.NASL
    descriptionFrom Red Hat Security Advisory 2018:3249 : An update for setup is now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having a security impact of Low. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link (s) in the References section. The setup package contains a set of important default system configuration and setup files. Examples include /etc/passwd, /etc/group, and /etc/profile. Other examples are the default lists of reserved user IDs, reserved ports, reserved protocols, allowed shells, allowed secure terminals. Security Fix(es) : * setup: nologin listed in /etc/shells violates security expectations (CVE-2018-1113) For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section. Additional Changes : For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.6 Release Notes linked from the References section.
    last seen2020-06-01
    modified2020-06-02
    plugin id118781
    published2018-11-07
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/118781
    titleOracle Linux 7 : setup (ELSA-2018-3249)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-F47268ACD5.NASL
    description - don
    last seen2020-06-05
    modified2019-01-03
    plugin id120908
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120908
    titleFedora 28 : setup (2018-f47268acd5)
  • NASL familyScientific Linux Local Security Checks
    NASL idSL_20181030_SETUP_ON_SL7_X.NASL
    descriptionSecurity Fix(es) : - setup: nologin listed in /etc/shells violates security expectations (CVE-2018-1113)
    last seen2020-03-18
    modified2018-11-27
    plugin id119199
    published2018-11-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/119199
    titleScientific Linux Security Update : setup on SL7.x (noarch) (20181030)
  • NASL familyAmazon Linux Local Security Checks
    NASL idAL2_ALAS-2019-1158.NASL
    descriptionSetup in Amazon Linux 2 added /sbin/nologin and /usr/sbin/nologin to /etc/shells. This violates security assumptions made by pam_shells and some daemons which allow access based on a user
    last seen2020-06-01
    modified2020-06-02
    plugin id122159
    published2019-02-14
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/122159
    titleAmazon Linux 2 : setup (ALAS-2019-1158)
  • NASL familyCentOS Local Security Checks
    NASL idCENTOS_RHSA-2018-3249.NASL
    descriptionAn update for setup is now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having a security impact of Low. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link (s) in the References section. The setup package contains a set of important default system configuration and setup files. Examples include /etc/passwd, /etc/group, and /etc/profile. Other examples are the default lists of reserved user IDs, reserved ports, reserved protocols, allowed shells, allowed secure terminals. Security Fix(es) : * setup: nologin listed in /etc/shells violates security expectations (CVE-2018-1113) For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section. Additional Changes : For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.6 Release Notes linked from the References section.
    last seen2020-06-01
    modified2020-06-02
    plugin id119001
    published2018-11-16
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/119001
    titleCentOS 7 : setup (CESA-2018:3249)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2018-1421.NASL
    descriptionAccording to the version of the setup package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - setup: nologin listed in /etc/shells violates security expectations (CVE-2018-1113) Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-05-06
    modified2018-12-28
    plugin id119910
    published2018-12-28
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/119910
    titleEulerOS 2.0 SP2 : setup (EulerOS-SA-2018-1421)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2018-1394.NASL
    descriptionAccording to the version of the setup package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - setup: nologin listed in /etc/shells violates security expectations (CVE-2018-1113) Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-05-15
    modified2018-12-10
    plugin id119522
    published2018-12-10
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/119522
    titleEulerOS 2.0 SP3 : setup (EulerOS-SA-2018-1394)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-1409.NASL
    descriptionAccording to the version of the setup package installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerability : - setup before version 2.11.4-1.fc28 in Fedora and Red Hat Enterprise Linux added /sbin/nologin and /usr/sbin/nologin to /etc/shells. This violates security assumptions made by pam_shells and some daemons which allow access based on a user
    last seen2020-06-01
    modified2020-06-02
    plugin id124912
    published2019-05-14
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/124912
    titleEulerOS Virtualization for ARM 64 3.0.1.0 : setup (EulerOS-SA-2019-1409)
  • NASL familyRed Hat Local Security Checks
    NASL idREDHAT-RHSA-2018-3249.NASL
    descriptionAn update for setup is now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having a security impact of Low. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link (s) in the References section. The setup package contains a set of important default system configuration and setup files. Examples include /etc/passwd, /etc/group, and /etc/profile. Other examples are the default lists of reserved user IDs, reserved ports, reserved protocols, allowed shells, allowed secure terminals. Security Fix(es) : * setup: nologin listed in /etc/shells violates security expectations (CVE-2018-1113) For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section. Additional Changes : For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.6 Release Notes linked from the References section.
    last seen2020-06-01
    modified2020-06-02
    plugin id118538
    published2018-10-31
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/118538
    titleRHEL 7 : setup (RHSA-2018:3249)

Redhat

advisories
  • bugzilla
    id1571094
    titleCVE-2018-1113 setup: nologin listed in /etc/shells violates security expectations
    oval
    OR
    • commentRed Hat Enterprise Linux must be installed
      ovaloval:com.redhat.rhba:tst:20070304026
    • AND
      • commentRed Hat Enterprise Linux 7 is installed
        ovaloval:com.redhat.rhba:tst:20150364027
      • commentsetup is earlier than 0:2.8.71-10.el7
        ovaloval:com.redhat.rhsa:tst:20183249001
      • commentsetup is signed with Red Hat redhatrelease2 key
        ovaloval:com.redhat.rhsa:tst:20183249002
    rhsa
    idRHSA-2018:3249
    released2018-10-30
    severityLow
    titleRHSA-2018:3249: setup security and bug fix update (Low)
  • rhsa
    idRHBA-2019:0327
rpmssetup-0:2.8.71-10.el7