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-780 Variant Incomplete
Use of RSA Algorithm without OAEP
This vulnerability occurs when an application implements RSA encryption but fails to use Optimal Asymmetric Encryption Padding (OAEP), significantly weakening the cryptographic protection.
Definition
What is CWE-780?
This vulnerability occurs when an application implements RSA encryption but fails to use Optimal Asymmetric Encryption Padding (OAEP), significantly weakening the cryptographic protection.
RSA encryption on its own has mathematical properties that make raw, unpadded messages vulnerable to analysis. Attackers can exploit these patterns to decrypt data without the private key. OAEP adds a layer of random padding before encryption, making every output unique and unpredictable, which is essential for secure RSA implementation in practice.
Without OAEP, encrypted data is far easier to compromise, especially in scenarios involving repeated or predictable messages. While SAST tools can detect this insecure pattern, managing this at scale is difficult; an ASPM like Plexicus can help you track and remediate these flaws across your entire stack, using AI to suggest the specific code fixes needed to implement OAEP correctly.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-780
Bisher sind in MITREs Katalog keine öffentlichen CVE-Referenzen mit dieser CWE verknüpft.
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
The example below attempts to build an RSA cipher.
public Cipher getRSACipher() {
Cipher rsa = null;
try {
rsa = javax.crypto.Cipher.getInstance("RSA/NONE/NoPadding");
}
catch (java.security.NoSuchAlgorithmException e) {
log("this should never happen", e);
}
catch (javax.crypto.NoSuchPaddingException e) {
log("this should never happen", e);
}
return rsa;
} Sicheres Codebeispiel
Secure Java
While the previous code successfully creates an RSA cipher, the cipher does not use padding. The following code creates an RSA cipher using OAEP.
public Cipher getRSACipher() {
Cipher rsa = null;
try {
rsa = javax.crypto.Cipher.getInstance("RSA/ECB/OAEPWithMD5AndMGF1Padding");
}
catch (java.security.NoSuchAlgorithmException e) {
log("this should never happen", e);
}
catch (javax.crypto.NoSuchPaddingException e) {
log("this should never happen", e);
}
return rsa;
} 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-780
- 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-780
CWE-780
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-780?
Wie gravierend ist CWE-780?
Welche Sprachen oder Plattformen sind von CWE-780 betroffen?
Wie kann ich CWE-780 verhindern?
Wie erkennt und behebt Plexicus CWE-780?
Wo erfahre ich mehr über CWE-780?
Frequently asked questions
Was ist CWE-780?
This vulnerability occurs when an application implements RSA encryption but fails to use Optimal Asymmetric Encryption Padding (OAEP), significantly weakening the cryptographic protection.
Wie gravierend ist CWE-780?
MITRE stuft die Exploit-Wahrscheinlichkeit als mittel ein — eine Ausnutzung ist realistisch, erfordert aber meist bestimmte Bedingungen.
Welche Sprachen oder Plattformen sind von CWE-780 betroffen?
MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.
Wie kann ich CWE-780 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-780?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-780 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-780?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/780.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-780
CWE-327 Parent
Use of a Broken or Risky Cryptographic Algorithm
The software relies on a cryptographic algorithm or protocol that is either fundamentally flawed or considered too weak by modern security…
CWE-1240 Sibling
Use of a Cryptographic Primitive with a Risky Implementation
This weakness occurs when a product uses a custom, unverified, or non-compliant implementation of a cryptographic algorithm instead of a…
CWE-328 Sibling
Use of Weak Hash
This vulnerability occurs when software uses a hashing algorithm that is cryptographically weak, allowing attackers to feasibly reverse…
CWE-916 Sibling
Use of Password Hash With Insufficient Computational Effort
This vulnerability occurs when a system protects passwords by hashing them, but uses a hashing algorithm that is too fast or…
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.