CVE Vulnerabilities

CVE-2020-15250

Incorrect Permission Assignment for Critical Resource

Published: Oct 12, 2020 | Modified: Nov 07, 2023
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS 2.x
1.9 LOW
AV:L/AC:M/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

In JUnit4 from version 4.7 and before 4.13.1, the test rule TemporaryFolder contains a local information disclosure vulnerability. On Unix like systems, the systems temporary directory is shared between all users on that system. Because of this, when files and directories are written into this directory they are, by default, readable by other users on that same system. This vulnerability does not allow other users to overwrite the contents of these directories or files. This is purely an information disclosure vulnerability. This vulnerability impacts you if the JUnit tests write sensitive information, like API keys or passwords, into the temporary folder, and the JUnit tests execute in an environment where the OS has other untrusted users. Because certain JDK file system APIs were only added in JDK 1.7, this this fix is dependent upon the version of the JDK you are using. For Java 1.7 and higher users: this vulnerability is fixed in 4.13.1. For Java 1.6 and lower users: no patch is available, you must use the workaround below. If you are unable to patch, or are stuck running on Java 1.6, specifying the java.io.tmpdir system environment variable to a directory that is exclusively owned by the executing user will fix this vulnerability. For more information, including an example of vulnerable code, see the referenced GitHub Security Advisory.

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
Junit4 Junit 4.7 *

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