Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.
CWE-550 Variant Incomplete
Server-generated Error Message Containing Sensitive Information
This vulnerability occurs when a web application or server returns detailed error messages that reveal sensitive internal information about the system.
Definition
What is CWE-550?
This vulnerability occurs when a web application or server returns detailed error messages that reveal sensitive internal information about the system.
When a server encounters an unexpected condition—like a database failure, a missing file, or an invalid request—it may generate an error message that leaks sensitive details. These details can include internal file paths, database schema information, server software versions, configuration settings, or even snippets of source code. While these messages are intended to help developers debug problems, they are often exposed to end-users, including potential attackers.
Attackers actively probe applications for these verbose errors because they provide a blueprint of the system's internals. This information significantly reduces the effort needed for a successful attack, as it can reveal software versions to target with known exploits, expose directory structures for path traversal attacks, or disclose SQL query fragments that help craft SQL injection payloads. The core risk isn't the error itself, but the free intelligence it hands to a malicious actor, accelerating further exploitation.
Real-world impact
Real-world CVEs caused by CWE-550
No public CVE references are linked to this CWE in MITRE's catalog yet.
How attackers exploit it
Step-by-step attacker path
- 1
Identify a code path that handles untrusted input without validation.
- 2
Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.
- 3
Deliver the payload through a normal request and observe the application's reaction.
- 4
Iterate until the response leaks data, executes attacker code, or escalates privileges.
Vulnerable code example
Vulnerable pseudo
MITRE has not published a code example for this CWE. The pattern below is illustrative — see Resources for canonical references.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Secure code example
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist
How to prevent CWE-550
- Architecture and Design / System Configuration Recommendations include designing and adding consistent error handling mechanisms which are capable of handling any user input to your web application, providing meaningful detail to end-users, and preventing error messages that might provide information useful to an attacker from being displayed.
Detection signals
How to detect CWE-550
Run dynamic application security testing against the live endpoint.
Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.
Code review: flag any new code that handles input from this surface without using the validated framework helpers.
CWE-550
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Frequently asked questions What is CWE-550?
How serious is CWE-550?
What languages or platforms are affected by CWE-550?
How can I prevent CWE-550?
How does Plexicus detect and fix CWE-550?
Where can I learn more about CWE-550?
Frequently asked questions
What is CWE-550?
This vulnerability occurs when a web application or server returns detailed error messages that reveal sensitive internal information about the system.
How serious is CWE-550?
MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.
What languages or platforms are affected by CWE-550?
MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.
How can I prevent CWE-550?
Recommendations include designing and adding consistent error handling mechanisms which are capable of handling any user input to your web application, providing meaningful detail to end-users, and preventing error messages that might provide information useful to an attacker from being displayed.
How does Plexicus detect and fix CWE-550?
Plexicus's SAST engine matches the data-flow signature for CWE-550 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.
Where can I learn more about CWE-550?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/550.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Related weaknesses
Weaknesses related to CWE-550
CWE-209 Parent
Generation of Error Message Containing Sensitive Information
This vulnerability occurs when an application reveals sensitive details about its internal systems, user data, or environment within error…
CWE-210 Sibling
Self-generated Error Message Containing Sensitive Information
This vulnerability occurs when an application detects a problem and generates its own error messages that accidentally expose sensitive…
CWE-211 Sibling
Externally-Generated Error Message Containing Sensitive Information
This vulnerability occurs when an application triggers an error message from an external component—like a database, interpreter, or…
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