Vulnerabilities > CVE-2019-9193 - OS Command Injection vulnerability in Postgresql

047910
CVSS 7.2 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
HIGH
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
postgresql
CWE-78
exploit available
metasploit

Summary

In PostgreSQL 9.3 through 11.2, the "COPY TO/FROM PROGRAM" function allows superusers and users in the 'pg_execute_server_program' group to execute arbitrary code in the context of the database's operating system user. This functionality is enabled by default and can be abused to run arbitrary operating system commands on Windows, Linux, and macOS. NOTE: Third parties claim/state this is not an issue because PostgreSQL functionality for ‘COPY TO/FROM PROGRAM’ is acting as intended. References state that in PostgreSQL, a superuser can execute commands as the server user without using the ‘COPY FROM PROGRAM’.

Vulnerable Configurations

Part Description Count
Application
Postgresql
136

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
  • Command Delimiters
    An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or a blacklist input validation, as opposed to whitelist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or blacklist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.
  • Exploiting Multiple Input Interpretation Layers
    An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
  • Argument Injection
    An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.
  • OS Command Injection
    In this type of an attack, an adversary injects operating system commands into existing application functions. An application that uses untrusted input to build command strings is vulnerable. An adversary can leverage OS command injection in an application to elevate privileges, execute arbitrary commands and compromise the underlying operating system.

Exploit-Db

idEDB-ID:46813
last seen2019-05-08
modified2019-05-08
published2019-05-08
reporterExploit-DB
sourcehttps://www.exploit-db.com/download/46813
titlePostgreSQL 9.3 - COPY FROM PROGRAM Command Execution (Metasploit)

Metasploit

descriptionInstallations running Postgres 9.3 and above have functionality which allows for the superuser and users with 'pg_execute_server_program' to pipe to and from an external program using COPY. This allows arbitrary command execution as though you have console access. This module attempts to create a new table, then execute system commands in the context of copying the command output into the table. This module should work on all Postgres systems running version 9.3 and above. For Linux & OSX systems, target 1 is used with cmd payloads such as: cmd/unix/reverse_perl For Windows Systems, target 2 is used with powershell payloads such as: cmd/windows/powershell_reverse_tcp Alternativly target 3 can be used to execute generic commands, such as a web_delivery meterpreter powershell payload or other customised command.
idMSF:EXPLOIT/MULTI/POSTGRES/POSTGRES_COPY_FROM_PROGRAM_CMD_EXEC
last seen2020-06-14
modified2019-04-12
published2019-03-21
references
reporterRapid7
sourcehttps://github.com/rapid7/metasploit-framework/blob/master//modules/exploits/multi/postgres/postgres_copy_from_program_cmd_exec.rb
titlePostgreSQL COPY FROM PROGRAM Command Execution

Packetstorm

data sourcehttps://packetstormsecurity.com/files/download/152757/postgres_copy_from_program_cmd_exec.rb.txt
idPACKETSTORM:152757
last seen2019-05-08
published2019-05-07
reporterJacob Wilkin
sourcehttps://packetstormsecurity.com/files/152757/PostgreSQL-COPY-FROM-PROGRAM-Command-Execution.html
titlePostgreSQL COPY FROM PROGRAM Command Execution