CWE-15: External Control of System or Configuration Setting

Code Examples & CVEs

Demonstrative Examples

The following C code accepts a number as one of its command line parameters and sets it as the host ID of the current machine.

Although a process must be privileged to successfully invoke sethostid(), unprivileged users may be able to invoke the program. The code in this example allows user input to directly control the value of a system setting. If an attacker provides a malicious value for host ID, the attacker can misidentify the affected machine on the network or cause other unintended behavior.

BadC

...sethostid(argv[1]);...

The following Java code snippet reads a string from an HttpServletRequest and sets it as the active catalog for a database Connection.

In this example, an attacker could cause an error by providing a nonexistent catalog name or connect to an unauthorized portion of the database.

BadJava

...conn.setCatalog(request.getParameter("catalog"));...

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-15 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-15, External Control of System or Configuration Setting, throughout the product lifecycle. Derive review questions, static or dynamic checks, and negative tests from the CWE's causal behavior; define the components and lifecycle stages each check covers; and retain findings with enough evidence to distinguish the root cause from symptoms and impacts. Track escapes and false negatives, then improve the verification plan after every confirmed occurrence.

NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and Technology

Apply Separation of Privilege controls for External Control of System or Configuration Setting

MITRE associates mitigation with Architecture and Design, and Implementation; the listed strategies include Separation of Privilege; documented detection approaches include Automated Static Analysis. Use these source-defined anchors to turn CWE-15 into implementation, review, and verification checks for the affected component.

CWE-15: External Control of System or Configuration Setting — MITRE CWE

Triage CWE-15 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-15, External Control of System or Configuration Setting, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.

Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security Agency

Apply precise root-cause mapping to CWE-15

Apply MITRE's full root-cause mapping guidance when using CWE-15, External Control of System or Configuration Setting. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.

CVE to CWE Root Cause Mapping Guidance — MITRE CWE

Validate CWE-15 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-15, External Control of System or Configuration Setting. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.

CVE to CWE Root Cause Mapping Quick Tips — MITRE CWE

Frequently Asked Questions

What is CWE-15: External Control of System or Configuration Setting?+

CWE-15: External Control of System or Configuration Setting is a Common Weakness Enumeration (CWE) entry maintained by MITRE. One or more system settings or configuration elements can be externally controlled by a user. Allowing external control of system settings can disrupt service or cause an application to behave in unexpected, and potentially malicious ways.

What are the security consequences of External Control of System or Configuration Setting?+

If exploited, CWE-15 (External Control of System or Configuration Setting) it can compromise Other, leading to outcomes such as Varies by Context.

How do you prevent or mitigate External Control of System or Configuration Setting?+

Recommended mitigations for CWE-15 include: Because setting manipulation covers a diverse set of functions, any attempt at illustrating it will inevitably be incomplete. Rather than searching for a tight-knit relationship between the functions addressed in the setting manipulation category, take a step back and consider the sorts of system values that an attacker should not be allowed to control. In general, do not allow user-provided or otherwise untrusted data to control sensitive values. The leverage that an attacker gains by controlling these values is not always immediately obvious, but do not underestimate the creativity of the attacker.

What is the difference between a CWE and a CVE?+

A CWE (Common Weakness Enumeration) like CWE-15 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.

CWE-15: External Control of System or Configuration Setting

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