ID CVE-2017-15131
Summary It was found that system umask policy is not being honored when creating XDG user directories, since Xsession sources xdg-user-dirs.sh before setting umask policy. This only affects xdg-user-dirs before 0.15.5 as shipped with Red Hat Enterprise Linux.
References
Vulnerable Configurations
  • Red Hat Enterprise Linux (RHEL) 7.0 (7)
    cpe:2.3:o:redhat:enterprise_linux:7.0
CVSS
Base: 4.6
Impact:
Exploitability:
CWE CWE-264
CAPEC
  • 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.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
nessus via4
  • NASL family Amazon Linux Local Security Checks
    NASL id AL2_ALAS-2018-1030.NASL
    description It was found that the system umask policy is not being honored when creating XDG user directories (~/Desktop etc) on first login. This could lead to user's files being inadvertently exposed to other local users.(CVE-2017-15131)
    last seen 2019-02-21
    modified 2018-08-31
    plugin id 110447
    published 2018-06-12
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=110447
    title Amazon Linux 2 : xdg-user-dirs (ALAS-2018-1030)
  • NASL family Huawei Local Security Checks
    NASL id EULEROS_SA-2018-1025.NASL
    description According to the version of the xdg-user-dirs package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - It was found that the system umask policy is not being honored when creating XDG user directories (~/Desktop etc) on first login. This could lead to user's files being inadvertently exposed to other local users.(CVE-2017-15131) 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 seen 2019-02-21
    modified 2018-11-13
    plugin id 106166
    published 2018-01-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=106166
    title EulerOS 2.0 SP2 : xdg-user-dirs (EulerOS-SA-2018-1025)
  • NASL family Scientific Linux Local Security Checks
    NASL id SL_20180410_XDG_USER_DIRS_ON_SL7_X.NASL
    description Security Fix(es) : - xdg-user-dirs, gnome-session: Xsession creation of XDG user directories does not honor system umask policy (CVE-2017-15131) Additional Changes :
    last seen 2019-02-21
    modified 2018-12-27
    plugin id 109459
    published 2018-05-01
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=109459
    title Scientific Linux Security Update : xdg-user-dirs on SL7.x x86_64
  • NASL family Huawei Local Security Checks
    NASL id EULEROS_SA-2018-1181.NASL
    description According to the version of the xdg-user-dirs package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - It was found that the system umask policy is not being honored when creating XDG user directories (~/Desktop etc) on first login. This could lead to user's files being inadvertently exposed to other local users.(CVE-2017-15131) 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 seen 2019-02-21
    modified 2018-11-13
    plugin id 110845
    published 2018-07-03
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=110845
    title EulerOS 2.0 SP3 : xdg-user-dirs (EulerOS-SA-2018-1181)
  • NASL family Red Hat Local Security Checks
    NASL id REDHAT-RHSA-2018-0842.NASL
    description An update for xdg-user-dirs 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. xdg-user-dirs is a tool to create and configure default desktop user directories such as the Music and the Desktop directories. Security Fix(es) : * xdg-user-dirs, gnome-session: Xsession creation of XDG user directories does not honor system umask policy (CVE-2017-15131) 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 7.5 Release Notes linked from the References section.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 108987
    published 2018-04-11
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=108987
    title RHEL 7 : xdg-user-dirs (RHSA-2018:0842)
  • NASL family Huawei Local Security Checks
    NASL id EULEROS_SA-2018-1024.NASL
    description According to the version of the xdg-user-dirs package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - It was found that the system umask policy is not being honored when creating XDG user directories (~/Desktop etc) on first login. This could lead to user's files being inadvertently exposed to other local users.(CVE-2017-15131) 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 seen 2019-02-21
    modified 2018-11-13
    plugin id 106165
    published 2018-01-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=106165
    title EulerOS 2.0 SP1 : xdg-user-dirs (EulerOS-SA-2018-1024)
  • NASL family Oracle Linux Local Security Checks
    NASL id ORACLELINUX_ELSA-2018-0842.NASL
    description From Red Hat Security Advisory 2018:0842 : An update for xdg-user-dirs 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. xdg-user-dirs is a tool to create and configure default desktop user directories such as the Music and the Desktop directories. Security Fix(es) : * xdg-user-dirs, gnome-session: Xsession creation of XDG user directories does not honor system umask policy (CVE-2017-15131) 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 7.5 Release Notes linked from the References section.
    last seen 2019-02-21
    modified 2018-09-05
    plugin id 109107
    published 2018-04-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=109107
    title Oracle Linux 7 : xdg-user-dirs (ELSA-2018-0842)
  • NASL family CentOS Local Security Checks
    NASL id CENTOS_RHSA-2018-0842.NASL
    description An update for xdg-user-dirs 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. xdg-user-dirs is a tool to create and configure default desktop user directories such as the Music and the Desktop directories. Security Fix(es) : * xdg-user-dirs, gnome-session: Xsession creation of XDG user directories does not honor system umask policy (CVE-2017-15131) 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 7.5 Release Notes linked from the References section.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 109373
    published 2018-04-27
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=109373
    title CentOS 7 : xdg-user-dirs (CESA-2018:0842)
redhat via4
advisories
bugzilla
id 1455094
title CVE-2017-15131 xdg-user-dirs, gnome-session: Xsession creation of XDG user directories does not honor system umask policy
oval
AND
  • comment xdg-user-dirs is earlier than 0:0.15-5.el7
    oval oval:com.redhat.rhsa:tst:20180842005
  • comment xdg-user-dirs is signed with Red Hat redhatrelease2 key
    oval oval:com.redhat.rhsa:tst:20180842006
  • OR
    • comment Red Hat Enterprise Linux 7 Client is installed
      oval oval:com.redhat.rhba:tst:20150364001
    • comment Red Hat Enterprise Linux 7 Server is installed
      oval oval:com.redhat.rhba:tst:20150364002
    • comment Red Hat Enterprise Linux 7 Workstation is installed
      oval oval:com.redhat.rhba:tst:20150364003
    • comment Red Hat Enterprise Linux 7 ComputeNode is installed
      oval oval:com.redhat.rhba:tst:20150364004
rhsa
id RHSA-2018:0842
released 2018-04-10
severity Low
title RHSA-2018:0842: xdg-user-dirs security and bug fix update (Low)
rpms xdg-user-dirs-0:0.15-5.el7
refmap via4
confirm https://bugzilla.redhat.com/show_bug.cgi?id=1412762
Last major update 09-01-2018 - 16:29
Published 09-01-2018 - 16:29
Last modified 11-04-2018 - 21:29
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