CWE-211: Externally-Generated Error Message Containing Sensitive Information

BaseIncomplete

The product performs an operation that triggers an external diagnostic or error message that is not directly generated or controlled by the product, such as an error generated by the programming language interpreter that a software application uses. The error can contain sensitive system information.

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Code Examples & CVEs

Demonstrative Examples

The following servlet code does not catch runtime exceptions, meaning that if such an exception were to occur, the container may display potentially dangerous information (such as a full stack trace).

BadJava

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {                         String username = request.getParameter("username");                                                        // May cause unchecked NullPointerException.                            if (username.length() < 10) {...}                      }

In the following Java example the class InputFileRead enables an input file to be read using a FileReader object. In the constructor of this class a default input file path is set to some directory on the local file system and the method setInputFile must be called to set the name of the input file to be read in the default directory. The method readInputFile will create the FileReader object and will read the contents of the file. If the method setInputFile is not called prior to calling the method readInputFile then the File object will remain null when initializing the FileReader object. A Java RuntimeException will be raised, and an error message will be output to the user.

However, the error message output to the user contains information regarding the default directory on the local file system. This information can be exploited and may lead to unauthorized access or use of the system. Any Java RuntimeExceptions that are handled should not expose sensitive information to the user.

BadJava

public class InputFileRead {                                               private File readFile = null;private FileReader reader = null;private String inputFilePath = null;private final String DEFAULT_FILE_PATH = "c:\\somedirectory\\";                            public InputFileRead() {inputFilePath = DEFAULT_FILE_PATH;}                            public void setInputFile(String inputFile) {                                                                                                   /* Assume appropriate validation / encoding is used and privileges / permissions are preserved */                                                                                             }                            public void readInputFile() {                               try {reader = new FileReader(readFile);...} catch (RuntimeException rex) {System.err.println("Error: Cannot open input file in the directory " + inputFilePath);System.err.println("Input file has not been set, call setInputFile method before calling readInputFile");                                                                    } catch (FileNotFoundException ex) {...}                                                           }                      }

Observed CVE Examples (6)

CVE-2004-1581

chain: product does not protect against direct request of an include file, leading to resultant path disclosure when the include file does not successfully execute.

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CVE-2004-1579

Single "'" inserted into SQL query leads to invalid SQL query execution, triggering full path disclosure. Possibly resultant from more general SQL injection issue.

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CVE-2005-0459

chain: product does not protect against direct request of a library file, leading to resultant path disclosure when the file does not successfully execute.

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CVE-2005-0443

invalid parameter triggers a failure to find an include file, leading to infoleak in error message.

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CVE-2005-0433

Various invalid requests lead to information leak in verbose error messages describing the failure to instantiate a class, open a configuration file, or execute an undefined function.

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CVE-2004-1101

Improper handling of filename request with trailing "/" causes multiple consequences, including information leak in Visual Basic error message.

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Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-211 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-211, Externally-Generated Error Message Containing Sensitive Information, 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 Compilation or Build Hardening controls for Externally-Generated Error Message Containing Sensitive Information

MITRE associates mitigation with System Configuration, Implementation, and Build and Compilation; the listed strategies include Compilation or Build Hardening, and Environment Hardening; recorded impacts include Read Application Data. Use these source-defined anchors to turn CWE-211 into implementation, review, and verification checks for the affected component.

CWE-211: Externally-Generated Error Message Containing Sensitive Information — MITRE CWE

Triage CWE-211 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-211, Externally-Generated Error Message Containing Sensitive Information, 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-211

Apply MITRE's full root-cause mapping guidance when using CWE-211, Externally-Generated Error Message Containing Sensitive Information. 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-211 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-211, Externally-Generated Error Message Containing Sensitive Information. 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-211: Externally-Generated Error Message Containing Sensitive Information?+

CWE-211: Externally-Generated Error Message Containing Sensitive Information is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product performs an operation that triggers an external diagnostic or error message that is not directly generated or controlled by the product, such as an error generated by the programming language interpreter that a software application uses. The error can contain sensitive system information.

What are the security consequences of Externally-Generated Error Message Containing Sensitive Information?+

If exploited, CWE-211 (Externally-Generated Error Message Containing Sensitive Information) it can compromise Confidentiality, leading to outcomes such as Read Application Data.

How do you prevent or mitigate Externally-Generated Error Message Containing Sensitive Information?+

Recommended mitigations for CWE-211 include: Configure the application's environment in a way that prevents errors from being generated. For example, in PHP, disable display_errors. Handle exceptions internally and do not display errors containing potentially sensitive information to a user. Create default error pages if necessary. The best way to prevent this weakness during implementation is to avoid any bugs that could trigger the external error message. This typically happens when the program encounters fatal errors, such as a divide-by-zero. You will not always be able to control the use of error pages, and you might not be using a language that handles exceptions.

Which programming languages are affected by Externally-Generated Error Message Containing Sensitive Information?+

CWE-211 commonly affects PHP and Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Externally-Generated Error Message Containing Sensitive Information?+

MITRE documents real CVEs mapped to CWE-211, including CVE-2004-1581, CVE-2004-1579, CVE-2005-0459, CVE-2005-0443 and CVE-2005-0433. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

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

A CWE (Common Weakness Enumeration) like CWE-211 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-211: Externally-Generated Error Message Containing Sensitive Information

Technical Details

Applicable To

Security Consequences

Scope

Impact

Mitigation Strategies

Phase

Description

Phase

Description

Phase

Description

Detection Methods

Code Examples & CVEs

Demonstrative Examples

Observed CVE Examples (6)

CWE Relationships

Parent Weaknesses

Source-backed guidance

Verify controls for CWE-211 with SSDF evidence

Apply Compilation or Build Hardening controls for Externally-Generated Error Message Containing Sensitive Information

Triage CWE-211 against known exploitation evidence

Apply precise root-cause mapping to CWE-211

Validate CWE-211 with root-cause mapping checks

Frequently Asked Questions

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