CWE-209: Generation of Error Message Containing Sensitive Information
The product generates an error message that includes sensitive information about its environment, users, or associated data.
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Overview
CWE-209 (Generation of Error Message Containing Sensitive Information) is a base-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.
Real-world CVEs
391 recorded CVEs are caused by CWE-209 (Generation of Error Message Containing Sensitive Information), including 3 in CISA's KEV (Known Exploited Vulnerabilities) catalog. KEVs are shown first. 98 new CWE-209 CVEs have been recorded so far in 2026 (94 in 2025).
- CVE-2024-29059CISA KEV
.NET Framework Information Disclosure Vulnerability
High · CVSS 8.7 · EPSS 100th2024-03-22 - CVE-2025-47813CISA KEVMedium · CVSS 5.3 · EPSS 99th2025-07-10
- CVE-2013-7331CISA KEVMedium · CVSS 5.3 · EPSS 99th2014-02-26
- CVE-2025-59872
HCL ZIE for Web is affetced by an Unrestricted File Upload vulnerability,
Critical · CVSS 9.8 · EPSS 38th2026-06-17 - CVE-2025-46658Critical · CVSS 9.8 · EPSS 30th2025-08-05
- CVE-2024-28285Critical · CVSS 9.8 · EPSS 41th2024-05-13
- CVE-2021-42777Critical · CVSS 9.8 · EPSS 61th2022-10-29
- CVE-2019-7612Critical · CVSS 9.8 · EPSS 83th2019-03-25
- CVE-2017-7551Critical · CVSS 9.8 · EPSS 71th2017-08-16
- CVE-2022-31229Critical · CVSS 9.6 · EPSS 52th2022-06-28
- CVE-2024-6980Critical · CVSS 9.2 · EPSS 44th2024-07-31
- CVE-2026-34045
Podman Desktop WebView Server Exposed
Critical · CVSS 9.1 · EPSS 39th2026-04-07
Showing 12 of 391 recorded CWE-209 CVEs. Track new ones as they are published and get AI-written analysis and fixes.
Monitor CWE-209 vulnerabilitiesCommon consequences
What can happen when CWE-209 is exploited.
Read Application Data
Affects: Confidentiality
Often this will either reveal sensitive information which may be used to launch another, more focused attack or disclose private information stored in the server. For example, an attempt to exploit a path traversal weakness (CWE-22) might yield the full pathname of the installed application. In turn, this could be used to select the proper number of ".." sequences to navigate to the targeted file. An attack using SQL injection (CWE-89) might not initially succeed, but an error message could reveal the malformed query, which would expose query logic and possibly even passwords or other sensitive information used within the query.
How it happens
When it is introduced
Typically introduced during these phases of the software lifecycle.
Applies to
Languages
How to prevent it
Practical mitigations for CWE-209, grouped by where in the lifecycle they apply.
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
Handle exceptions internally and do not display errors containing potentially sensitive information to a user.
Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
Effectiveness: Defense in Depth — This makes it easier to spot places in the code where data is being used that is unencrypted.
Debugging information should not make its way into a production release.
Debugging information should not make its way into a production release.
Where available, configure the environment to use less verbose error messages. For example, in PHP, disable the display_errors setting during configuration, or at runtime using the error_reporting() function.
Create default error pages or messages that do not leak any information.
How to detect it
Manual Analysis
This weakness generally requires domain-specific interpretation using manual analysis. However, the number of potential error conditions may be too large to cover completely within limited time constraints.
Effectiveness: High
Automated Analysis
Automated methods may be able to detect certain idioms automatically, such as exposed stack traces or pathnames, but violation of business rules or privacy requirements is not typically feasible.
Effectiveness: Moderate
Automated Dynamic Analysis
This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
Error conditions may be triggered with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior.
Effectiveness: Moderate
Manual Dynamic Analysis
Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the program under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself.
Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Code examples
Illustrative examples from MITRE showing how the weakness appears in code.
In the following example, sensitive information might be printed depending on the exception that occurs.
Vulnerable example
try {If an exception related to SQL is handled by the catch, then the output might contain sensitive information such as SQL query structure or private information. If this output is redirected to a web user, this may represent a security problem.
This code tries to open a database connection, and prints any exceptions that occur.
Vulnerable example
//print exception message that includes exception message and configuration file location
try {If an exception occurs, the printed message exposes the location of the configuration file the script is using. An attacker can use this information to target the configuration file (perhaps exploiting a Path Traversal weakness). If the file can be read, the attacker could gain credentials for accessing the database. The attacker may also be able to replace the file with a malicious one, causing the application to use an arbitrary database.
The following code generates an error message that leaks the full pathname of the configuration file.
Vulnerable example
# avoid CWE-22, CWE-78, others.
$ConfigDir = "/home/myprog/config";If this code is running on a server, such as a web application, then the person making the request should not know what the full pathname of the configuration directory is. By submitting a username that does not produce a $file that exists, an attacker could get this pathname. It could then be used to exploit path traversal or symbolic link following problems that may exist elsewhere in the application.
In the example below, the method getUserBankAccount retrieves a bank account object from a database using the supplied username and account number to query the database. If an SQLException is raised when querying the database, an error message is created and output to a log file.
Vulnerable example
public BankAccount getUserBankAccount(String username, String accountNumber) {The error message that is created includes information about the database query that may contain sensitive information about the database or query logic. In this case, the error message will expose the table name and column names used in the database. This data could be used to simplify other attacks, such as SQL injection (CWE-89) to directly access the database.
Illustrative examples
Real CVEs that MITRE cites as examples of this weakness.
- CVE-2008-2049 — POP3 server reveals a password in an error message after multiple APOP commands are sent. Might be resultant from another weakness.
- CVE-2007-5172 — Program reveals password in error message if attacker can trigger certain database errors.
- CVE-2008-4638 — Composite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (CWE-209).
- CVE-2008-1579 — Existence of user names can be determined by requesting a nonexistent blog and reading the error message.
- CVE-2007-1409 — Direct request to library file in web application triggers pathname leak in error message.
- CVE-2008-3060 — Malformed input to login page causes leak of full path when IMAP call fails.
- CVE-2005-0603 — Malformed regexp syntax leads to information exposure in error message.
- CVE-2017-9615 — verbose logging stores admin credentials in a world-readablelog file
- CVE-2018-1999036 — SSH password for private key stored in build log
Terminology & mappings
Mapped taxonomies
- CLASP: Accidental leaking of sensitive information through error messages
- OWASP Top Ten 2007: Information Leakage and Improper Error Handling (A6) — CWE More Specific fit
- OWASP Top Ten 2004: Improper Error Handling (A7) — CWE More Specific fit
- OWASP Top Ten 2004: Insecure Configuration Management (A10) — CWE More Specific fit
- The CERT Oracle Secure Coding Standard for Java (2011): Do not allow exceptions to expose sensitive information (ERR01-J)
- Software Fault Patterns: Exposed Data (SFP23)
Attack patterns
CAPEC attack patterns that exploit this weakness.
Frequently asked questions
Common questions about CWE-209.
- What is CWE-209?
- The product generates an error message that includes sensitive information about its environment, users, or associated data.
- What CVEs are caused by CWE-209?
- 391 recorded CVEs are attributed to CWE-209, including CVE-2024-29059, CVE-2025-47813, CVE-2013-7331. 3 are listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.
- Is CWE-209 part of the OWASP Top 10?
- CWE-209 maps to OWASP Top Ten 2007: Information Leakage and Improper Error Handling (A6) in the OWASP security taxonomy.
- How do you prevent CWE-209?
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- How is CWE-209 detected?
- Manual Analysis: This weakness generally requires domain-specific interpretation using manual analysis. However, the number of potential error conditions may be too large to cover completely within limited time constraints.
- What are the consequences of CWE-209?
- Exploiting CWE-209 can lead to: Read Application Data.
- Is CWE-209 actively exploited?
- Yes. 3 CWE-209 vulnerabilities are in CISA's KEV catalog of actively exploited flaws, out of 391 recorded CVEs.
References
- MITRE CWE definition (CWE-209) (opens in a new tab)
- CWE-209 vulnerabilities on NVD (opens in a new tab)
- Learn: What is a CWE?
Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.
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