CVE-2019-25066 (published 2022-06-09T17:15Z)

A vulnerability has been found in ajenti 2.1.31 and classified as critical. This vulnerability affects unknown code of the component API. The manipulation leads to privilege escalation. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 2.1.32 is able to address this issue. The name of the patch is 7aa146b724e0e20cfee2c71ca78fafbf53a8767c. It is recommended to upgrade the affected component.

Severity: MEDIUM
CVSS v2 base score: 6.5 (AV:N/AC:L/Au:S/C:P/I:P/A:P)
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/ajenti/ajenti
commit_details: repo_url: https://github.com/ajenti/ajenti
author: Eugene Pankov
author_date: 2019-10-05 07:06:48-07:00
msg: fixed shell injection in os auth provider
repository: repo_url: https://github.com/ajenti/ajenti
repo_name: ajenti/ajenti
description: Ajenti Core and stock plugins
repo_language: Python
owner: ajenti
file_changes: filename: auth.py
change_type: ModificationType.MODIFY
diff: @@ -5,6 +5,7 @@ import pwd
 import subprocess
 import syslog
 from jadi import component, service, interface
+from six import PY3
 
 import aj
 from aj.api.http import BaseHttpHandler
@@ -99,8 +100,14 @@ class OSAuthenticationProvider(AuthenticationProvider):
 
     def authenticate(self, username, password):
         child = None
+
+        if PY3:
+            from shlex import quote
+        else:
+            from pipes import quote
+
         try:
-            child = pexpect.spawn('/bin/sh', ['-c', '/bin/su -c "/bin/echo SUCCESS" - %s' % username], timeout=5)
+            child = pexpect.spawn('/bin/sh', ['-c', '/bin/su -c "/bin/echo SUCCESS" - %s' % quote(username)], timeout=5)
             child.expect('.*:')
             child.sendline(password)
             result = child.expect(['su: .*', 'SUCCESS'])

programming_language: Python