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-347 Base Draft
Improper Verification of Cryptographic Signature
This vulnerability occurs when an application fails to properly check the digital signature on data, or skips the verification step entirely, allowing tampered or forged information to be accepted…
Definition
What is CWE-347?
This vulnerability occurs when an application fails to properly check the digital signature on data, or skips the verification step entirely, allowing tampered or forged information to be accepted as legitimate.
Cryptographic signatures are essential for verifying the authenticity and integrity of data, such as software updates, authentication tokens, or API messages. When an application doesn't validate these signatures correctly—by using the wrong key, ignoring expiration, or not checking the result—attackers can inject malicious data, escalate privileges, or bypass security controls. This often happens due to misunderstood libraries, manual implementation of complex protocols, or simply overlooking the verification step after signature extraction.
Detecting these flaws requires checking code paths where signatures are processed, ensuring robust key management, and using up-to-date libraries. While SAST tools can flag missing verification calls, managing this at scale across microservices and third-party dependencies is challenging. An ASPM like Plexicus helps by correlating these findings across your entire stack, and its AI can provide automated, context-aware remediation suggestions to fix the vulnerable code efficiently.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-347
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Does not properly verify signatures for "trusted" entities.
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Insufficient verification allows spoofing.
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Insufficient verification allows spoofing.
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Accepts a configuration file without a Message Integrity Check (MIC) signature.
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 following code, a JarFile object is created from a downloaded file.
File f = new File(downloadedFilePath);
JarFile jf = new JarFile(f); 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-347
- Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
- Implementation Validate input at trust boundaries; use allowlists, not denylists.
- Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
- Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
- Operation Monitor logs for the runtime signals listed in the next section.
Erkennungssignale
How to detect CWE-347
Plexicus erkennt CWE-347 automatisch und öffnet in unter 60 Sekunden einen Fix-PR.
Codex Remedium scannt jeden Commit, identifiziert genau diese Schwachstelle und liefert einen reviewer-ready Pull Request mit dem Patch. Keine Tickets. Keine Hand-offs.
Häufig gestellte Fragen Was ist CWE-347?
Wie gravierend ist CWE-347?
Welche Sprachen oder Plattformen sind von CWE-347 betroffen?
Wie kann ich CWE-347 verhindern?
Wie erkennt und behebt Plexicus CWE-347?
Wo erfahre ich mehr über CWE-347?
Frequently asked questions
Was ist CWE-347?
This vulnerability occurs when an application fails to properly check the digital signature on data, or skips the verification step entirely, allowing tampered or forged information to be accepted as legitimate.
Wie gravierend ist CWE-347?
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-347 betroffen?
MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.
Wie kann ich CWE-347 verhindern?
Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.
Wie erkennt und behebt Plexicus CWE-347?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-347 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-347?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/347.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-347
CWE-345 Parent
Insufficient Verification of Data Authenticity
This vulnerability occurs when an application fails to properly check where data comes from or confirm its legitimacy, allowing untrusted…
CWE-1293 Sibling
Missing Source Correlation of Multiple Independent Data
This vulnerability occurs when a system trusts a single source of data without verification, making it impossible to detect if that source…
CWE-346 Sibling
Origin Validation Error
This vulnerability occurs when an application fails to properly confirm the true origin of incoming data or communication, allowing…
CWE-348 Sibling
Use of Less Trusted Source
This vulnerability occurs when a system has access to multiple sources for the same critical data, but it chooses to rely on the less…
CWE-349 Sibling
Acceptance of Extraneous Untrusted Data With Trusted Data
This vulnerability occurs when a system processes both trusted and untrusted data together, but fails to separate them. The application…
CWE-351 Sibling
Insufficient Type Distinction
This vulnerability occurs when an application fails to properly differentiate between different types of data or objects, leading to…
CWE-352 Sibling
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) happens when a web application cannot reliably tell if a user actually intended to submit a request,…
CWE-353 Sibling
Missing Support for Integrity Check
This vulnerability occurs when a system uses a communication protocol that lacks built-in integrity verification, such as a checksum or…
CWE-354 Sibling
Improper Validation of Integrity Check Value
This vulnerability occurs when software fails to properly check the integrity of data by validating its checksum or hash value. Without…
Ressourcen
Further reading
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