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.)
CWE-617 Base Draft
Reachable Assertion
A reachable assertion occurs when an attacker can trigger an assert() statement or similar debugging check, causing the application to crash or behave in a more disruptive way than intended. This…
Definition
What is CWE-617?
A reachable assertion occurs when an attacker can trigger an assert() statement or similar debugging check, causing the application to crash or behave in a more disruptive way than intended. This turns a helpful development tool into a denial-of-service vulnerability.
Assertions are meant to catch logic errors during development, but if left in production code, they can be weaponized. An attacker who discovers the trigger condition can force the application to exit abruptly, disrupting service for all users. For instance, a single triggered assert() in a multi-connection server could terminate every active connection, causing widespread outage.
While SAST tools can flag the presence of assertions, managing this risk at scale across a large codebase is challenging. An ASPM platform like Plexicus helps by continuously tracking these flaws in production, and its AI can recommend specific fixes—such as replacing the assert with proper error handling—saving significant manual remediation time.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-617
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Chain: function in web caching proxy does not correctly check a return value (CWE-253) leading to a reachable assertion (CWE-617)
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FTP server allows remote attackers to cause a denial of service (daemon abort) via crafted commands which trigger an assertion failure.
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Chat client allows remote attackers to cause a denial of service (crash) via a long message string when connecting to a server, which causes an assertion failure.
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Product allows remote attackers to cause a denial of service (daemon crash) via LDAP BIND requests with long authcid names, which triggers an assertion failure.
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Product allows remote attackers to cause a denial of service (crash) via certain queries, which cause an assertion failure.
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Chain: security monitoring product has an off-by-one error that leads to unexpected length values, triggering an assertion.
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Anti-virus product has assert error when line length is non-numeric.
Wie Angreifer es ausnutzen
Angreiferpfad Schritt für Schritt
- 1
Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.
- 2
Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.
- 3
Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.
- 4
Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.
Verwundbares Codebeispiel
Vulnerable Java
In the excerpt below, an AssertionError (an unchecked exception) is thrown if the user hasn't entered an email address in an HTML form.
String email = request.getParameter("email_address");
assert email != null; Sicheres Codebeispiel
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.
Präventions-Checkliste
How to prevent CWE-617
- Implementation Make sensitive open/close operation non reachable by directly user-controlled data (e.g. open/close resources)
- Implementation Perform input validation on user data.
Erkennungssignale
How to detect CWE-617
CWE-617
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.
Häufig gestellte Fragen Was ist CWE-617?
Wie gravierend ist CWE-617?
Welche Sprachen oder Plattformen sind von CWE-617 betroffen?
Wie kann ich CWE-617 verhindern?
Wie erkennt und behebt Plexicus CWE-617?
Wo erfahre ich mehr über CWE-617?
Frequently asked questions
Was ist CWE-617?
A reachable assertion occurs when an attacker can trigger an assert() statement or similar debugging check, causing the application to crash or behave in a more disruptive way than intended. This turns a helpful development tool into a denial-of-service vulnerability.
Wie gravierend ist CWE-617?
MITRE hat für diese Schwachstelle keine Exploit-Wahrscheinlichkeit veröffentlicht. Behandle sie als mittlere Auswirkung, bis dein Threat Model anderes belegt.
Welche Sprachen oder Plattformen sind von CWE-617 betroffen?
MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.
Wie kann ich CWE-617 verhindern?
Make sensitive open/close operation non reachable by directly user-controlled data (e.g. open/close resources) Perform input validation on user data.
Wie erkennt und behebt Plexicus CWE-617?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-617 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.
Wo erfahre ich mehr über CWE-617?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/617.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-617
CWE-670 Parent
Always-Incorrect Control Flow Implementation
This weakness occurs when a section of code is structured in a way that always executes incorrectly, regardless of input or conditions.…
CWE-480 Sibling
Use of Incorrect Operator
This vulnerability occurs when a developer mistakenly uses the wrong operator in their code, leading to unintended and potentially…
CWE-483 Sibling
Incorrect Block Delimitation
This vulnerability occurs when a developer fails to use explicit braces or delimiters to group multiple statements within a block, leading…
CWE-484 Sibling
Omitted Break Statement in Switch
This vulnerability occurs when a developer forgets to include a 'break' statement inside a switch-case block. Without it, the code…
CWE-698 Sibling
Execution After Redirect (EAR)
Execution After Redirect (EAR) occurs when a web application sends a redirect response to a user's browser but continues to run…
CWE-783 Sibling
Operator Precedence Logic Error
This vulnerability occurs when a developer writes a conditional expression where the intended logic is broken due to misunderstanding or…
Ressourcen
Further reading
Bereit, das Wesentliche zu validieren?
Bereit zu validieren, was zählt.
Plexicus ist Proof-Driven AppSec: validierte Funde, kontextuelles Verständnis und geprüfte Remediation — in Evidenz verankert, mit Ihnen gescoped.