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Description
The software constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
Modes of Introduction:
– Architecture and Design
Likelihood of Exploit: High
Related Weaknesses
CWE-74
CWE-74
Consequences
Integrity, Confidentiality, Availability: Execute Unauthorized Code or Commands
If a malicious user injects a character (such as a semi-colon) that delimits the end of one command and the beginning of another, it may be possible to then insert an entirely new and unrelated command that was not intended to be executed.
Potential Mitigations
Phase: Architecture and Design
Effectiveness:
Description:
If at all possible, use library calls rather than external processes to recreate the desired functionality.
Phase: Implementation
Effectiveness:
Description:
If possible, ensure that all external commands called from the program are statically created.
Phase: Implementation
Effectiveness:
Description:
Phase: Operation
Effectiveness:
Description:
Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
Phase: System Configuration
Effectiveness:
Description:
Assign permissions to the software system that prevents the user from accessing/opening privileged files.
CVE References
- CVE-1999-0067
- Canonical example of OS command injection. CGI program does not neutralize “|” metacharacter when invoking a phonebook program.
- CVE-2019-12921
- image program allows injection of commands in “Magick Vector Graphics (MVG)” language.
- CVE-2020-11698
- anti-spam product allows injection of SNMP commands into confiuration file
