CAPEC-15
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 denylist input validation, as opposed to allowlist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or denylist. 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.
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Explain the attack pattern CAPEC-15: Command Delimiters: how it unfolds, what it needs and how to prevent and detect it in my systems. Use https://capec.mitre.org/data/definitions/15.html and https://cve.bz/cve/capec/15?via=ask-ai-copy, which lists recent CVEs with the weaknesses it exploits. Cite the sources.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this attack pattern's id and public links.
How the attack unfolds
Explore
The attacker looks for a way in.
[Assess Target Runtime Environment] In situations where the runtime environment is not implicitly known, the attacker makes connections to the target system and tries to determine the system's runtime environment. Knowing the environment is vital to choosing the correct delimiters.
4 techniques
- Port mapping using network connection-based software (e.g., nmap, nessus, etc.)
- Port mapping by exploring the operating system (netstat, sockstat, etc.)
- TCP/IP Fingerprinting
- Induce errors to find informative error messages
[Survey the Application] The attacker surveys the target application, possibly as a valid and authenticated user
2 techniques
- Spidering web sites for all available links
- Inventory all application inputs
Experiment
They probe what they found.
[Attempt delimiters in inputs] The attacker systematically attempts variations of delimiters on known inputs, observing the application's response each time.
3 techniques
- Inject command delimiters using network packet injection tools (netcat, nemesis, etc.)
- Inject command delimiters using web test frameworks (proxies, TamperData, custom programs, etc.)
- Enter command delimiters directly in input fields.
Exploit
They carry out the attack.
[Use malicious command delimiters] The attacker uses combinations of payload and carefully placed command delimiters to attack the software.
Prerequisites
Software's input validation or filtering must not detect and block presence of additional malicious command.
Skills required
- Medium skill
The attacker has to identify injection vector, identify the specific commands, and optionally collect the output, i.e. from an interactive session.
Resources required
Ability to communicate synchronously or asynchronously with server. Optionally, ability to capture output directly through synchronous communication or other method such as FTP.
Consequences
| Impact | Affects | Note |
|---|---|---|
| Execute Unauthorized Commands | Confidentiality, Integrity, Availability | Run Arbitrary Code |
| Read Data | Confidentiality |
Mitigations
Design: Perform allowlist validation against a positive specification for command length, type, and parameters.
Design: Limit program privileges, so if commands circumvent program input validation or filter routines then commands do not running under a privileged account
Implementation: Perform input validation for all remote content.
Implementation: Use type conversions such as JDBC prepared statements.
Weaknesses it exploits
- CWE-77 Improper Neutralization of Special Elements used in a Command
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
- CWE-93 Improper Neutralization of CRLF Sequences
- CWE-138 Improper Neutralization of Special Elements
- CWE-140 Improper Neutralization of Delimiters
- CWE-146 Improper Neutralization of Expression/Command Delimiters
- CWE-154 Improper Neutralization of Variable Name Delimiters
- CWE-157 Failure to Sanitize Paired Delimiters
- CWE-184 Incomplete List of Disallowed Inputs
- CWE-185 Incorrect Regular Expression
- CWE-697 Incorrect Comparison
Recent CVEs with these weaknesses
- 7.2CVE-2026-105425
OS command injection in Ivanti Sentry before versions 10.7.4, 10.8.3, and 11.0.0 as well as in Ivanti EPMM before version 12.10.0.1, 12.9.0.3, and 12.8.0.5 allows a remote authenticated attacker with admin privileges to achieve remote code…
- 8.8CVE-2026-12573
Zoho Corporation ManageEngine DDI Central versions 6200 and below are vulnerable to Cisco IOS command injection via DHCP pool name leading to arbitrary commands on managed Cisco routers.
- 8.8CVE-2026-123717
OS command injection in the pass and bitwarden credential providers in Eclipse Foundation Eclipse Otterdog through 1.7.1 allows a user able to modify an organization configuration to execute arbitrary commands with the privileges of the op…
- 7.0CVE-2026-109830
A vulnerability has been identified in meta-iot2050 (All versions >= V01.03.01). Affected devices take parts from a configuration file and execute them unchecked. This could allow an attacker which is able to manipulate the configuration f…
- 8.0CVE-2026-95646
Zoho Corporation ManageEngine DDI Central versions 6500 and below are vulnerable to a Unicode-based command injection vulnerability in the Cisco IOS DHCP configuration functionality. This vulnerability could allow cluster-scoped operators …
- 8.6CVE-2026-60039
A high privileged remote attacker can perform a code injection in the backends backup restore function leading to code execution. This can result in a total loss of confidentiality, integrity and availability.
- 8.6CVE-2026-60038
A high privileged remote attacker can perform an OpenSSL code injection in the backends ImportPKCS12 function leading to code execution. This can result in a total loss of confidentiality, integrity and availability.
- 8.6CVE-2026-60037
A high privileged remote attacker can perform an OpenSSL code injection in the frontends device importer function leading to code execution. This can result in a total loss of confidentiality, integrity and availability.
The newest records naming one of them. Each weakness's page lists them all.
Related attack patterns
Examples
By appending special characters, such as a semicolon or other commands that are executed by the target proces…
By appending special characters, such as a semicolon or other commands that are executed by the target process, the attacker is able to execute a wide variety of malicious commands in the target process space, utilizing the target's inherited permissions, against any resource the host has access to. The possibilities are vast including injection attacks against RDBMS (SQL Injection), directory servers (LDAP Injection), XML documents (XPath and XQuery Injection), and command line shells. In many injection attacks, the results are converted back to strings and displayed to the client process such as a web browser without tripping any security alarms, so the network firewall does not log any out of the ordinary behavior.
LDAP servers house critical identity assets such as user, profile, password, and group information that is used to authenticate and authorize users. An attacker that can query the directory at will and execute custom commands against the directory server is literally working with the keys to the kingdom in many enterprises. When user, organizational units, and other directory objects are queried by building the query string directly from user input with no validation, or other conversion, then the attacker has the ability to use any LDAP commands to query, filter, list, and crawl against the LDAP server directly in the same manner as SQL injection gives the ability to the attacker to run SQL commands on the database.
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