CVE Vulnerabilities

CVE-2017-1000095

Incorrect Permission Assignment for Critical Resource

Published: Oct 05, 2017 | Modified: Oct 03, 2019
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
4 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N
RedHat/V2
RedHat/V3
8.8 IMPORTANT
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Ubuntu

The default whitelist included the following unsafe entries: DefaultGroovyMethods.putAt(Object, String, Object); DefaultGroovyMethods.getAt(Object, String). These allowed circumventing many of the access restrictions implemented in the script sandbox by using e.g. currentBuild[‘rawBuild’] rather than currentBuild.rawBuild. Additionally, the following entries allowed accessing private data that would not be accessible otherwise due to script security: groovy.json.JsonOutput.toJson(Closure); groovy.json.JsonOutput.toJson(Object).

Weakness

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Affected Software

Name Vendor Start Version End Version
Script_security Jenkins 1.34 1.34
Red Hat OpenShift Container Platform 3.6 RedHat jenkins-plugin-script-security-0:1.29-1.el7 *

Potential Mitigations

  • Run the code in a “jail” or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
  • OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
  • This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
  • Be careful to avoid CWE-243 and other weaknesses related to jails.

References