CVE-2023-28627 (published 2023-03-27T21:15Z)

pymedusa is an automatic video library manager for TV Shows. In versions prior 1.0.12 an attacker with access to the web interface can update the git executable path in /config/general/ > advanced settings with arbitrary OS commands. An attacker may exploit this vulnerability to take execute arbitrary OS commands as the user running the pymedusa program. Users are advised to upgrade. There are no known workarounds for this vulnerability.

CVSS v3 base score: 8.8, HIGH (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-78
cwe_name: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
description: The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
extended_description: 
		   This weakness can lead to a vulnerability in environments in which the attacker does not have direct access to the operating system, such as in web applications. Alternately, if the weakness occurs in a privileged program, it could allow the attacker to specify commands that normally would not be accessible, or to call alternate commands with privileges that the attacker does not have. The problem is exacerbated if the compromised process does not follow the principle of least privilege, because the attacker-controlled commands may run with special system privileges that increases the amount of damage.
            There are at least two subtypes of OS command injection:
               
				 The application intends to execute a single, fixed program that is under its own control. It intends to use externally-supplied inputs as arguments to that program. For example, the program might use system("nslookup [HOSTNAME]") to run nslookup and allow the user to supply a HOSTNAME, which is used as an argument. Attackers cannot prevent nslookup from executing. However, if the program does not remove command separators from the HOSTNAME argument, attackers could place the separators into the arguments, which allows them to execute their own program after nslookup has finished executing.
				 The application accepts an input that it uses to fully select which program to run, as well as which commands to use. The application simply redirects this entire command to the operating system. For example, the program might use "exec([COMMAND])" to execute the [COMMAND] that was supplied by the user. If the COMMAND is under attacker control, then the attacker can execute arbitrary commands or programs. If the command is being executed using functions like exec() and CreateProcess(), the attacker might not be able to combine multiple commands together in the same line.
               
            From a weakness standpoint, these variants represent distinct programmer errors. In the first variant, the programmer clearly intends that input from untrusted parties will be part of the arguments in the command to be executed. In the second variant, the programmer does not intend for the command to be accessible to any untrusted party, but the programmer probably has not accounted for alternate ways in which malicious attackers can provide input.
         
         

Fix information:
repo_url: https://github.com/pymedusa/Medusa
commit_details: repo_url: https://github.com/pymedusa/Medusa
author: Dario
author_date: 2023-02-22 11:23:45+01:00
msg: Ensure that git_path is a valid file (#11138)

* Ensure that git_path is a valid file

* Update github_updater.py
repository: repo_url: https://github.com/pymedusa/Medusa
repo_name: pymedusa/Medusa
description: Automatic Video Library Manager for TV Shows. It watches for new episodes of your favorite shows, and when they are posted it does its magic.
repo_language: Python
owner: pymedusa
file_changes: filename: github_updater.py
change_type: ModificationType.MODIFY
diff: @@ -3,6 +3,7 @@
 from __future__ import unicode_literals
 
 import logging
+import os
 import platform
 import re
 import subprocess
@@ -72,11 +73,7 @@ class GitUpdateManager(UpdateManager):
 
     def _find_working_git(self):
         test_cmd = 'version'
-
-        if app.GIT_PATH:
-            main_git = '"' + app.GIT_PATH + '"'
-        else:
-            main_git = 'git'
+        main_git = app.GIT_PATH or 'git'
 
         log.debug(u'Checking if we can use git commands: {0} {1}', main_git, test_cmd)
         _, _, exit_status = self._run_git(main_git, test_cmd)
@@ -126,6 +123,11 @@ class GitUpdateManager(UpdateManager):
                 exit_status = 1
                 return output, err, exit_status
 
+        if git_path != 'git' and not os.path.isfile(git_path):
+            log.warning(u"Invalid git specified, can't use git commands")
+            exit_status = 1
+            return output, err, exit_status
+
         # If we have a valid git remove the git warning
         # String will be updated as soon we check github
         app.NEWEST_VERSION_STRING = None

programming_language: Python