Führe statische Analyse (SAST) auf der Codebasis aus und suche im Datenfluss nach dem unsicheren Muster.
CWE-833 Base Incomplete
Deadlock
Deadlock occurs when two or more threads or processes become permanently stuck, each waiting for the other to release a shared resource like a lock or mutex, preventing any of them from progressing.
Definition
What is CWE-833?
Deadlock occurs when two or more threads or processes become permanently stuck, each waiting for the other to release a shared resource like a lock or mutex, preventing any of them from progressing.
Deadlock is a common concurrency bug that arises when threads or processes enter a circular waiting pattern. For example, Thread A holds Lock 1 and waits for Lock 2, while Thread B holds Lock 2 and waits for Lock 1. Since neither can proceed without the resource the other holds, the entire system grinds to a halt. This often stems from inconsistent or poorly managed locking order across different parts of the code.
To prevent deadlocks, developers should enforce a strict, global order for acquiring multiple locks and use timeouts or non-blocking lock attempts. Techniques like lock hierarchies, deadlock detection algorithms, and minimizing the scope and duration of locks are crucial. Understanding and managing these dependencies is essential for building robust, multi-threaded applications that avoid this silent failure state.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-833
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A bug in some Intel Pentium processors allow DoS (hang) via an invalid "CMPXCHG8B" instruction, causing a deadlock
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OS deadlock
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OS deadlock involving 3 separate functions
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deadlock in library
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deadlock triggered by packets that force collisions in a routing table
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read/write deadlock between web server and script
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web server deadlock involving multiple listening connections
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multiple simultaneous calls to the same function trigger deadlock.
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 pseudo
MITRE hat kein Codebeispiel für diese CWE veröffentlicht. Das untenstehende Muster ist illustrativ — kanonische Referenzen findest du unter Ressourcen.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} 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-833
- 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-833
Führe dynamische Application-Security-Tests gegen den Live-Endpoint aus.
Beobachte Runtime-Logs auf ungewöhnliche Exception-Traces, fehlerhafte Eingaben oder Versuche, Autorisierung zu umgehen.
Code Review: Markiere jeden neuen Code, der Eingaben von dieser Oberfläche ohne validierte Framework-Helper verarbeitet.
CWE-833
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-833?
Wie gravierend ist CWE-833?
Welche Sprachen oder Plattformen sind von CWE-833 betroffen?
Wie kann ich CWE-833 verhindern?
Wie erkennt und behebt Plexicus CWE-833?
Wo erfahre ich mehr über CWE-833?
Frequently asked questions
Was ist CWE-833?
Deadlock occurs when two or more threads or processes become permanently stuck, each waiting for the other to release a shared resource like a lock or mutex, preventing any of them from progressing.
Wie gravierend ist CWE-833?
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-833 betroffen?
MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.
Wie kann ich CWE-833 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-833?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-833 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-833?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/833.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-833
CWE-667 Parent
Improper Locking
This vulnerability occurs when a program fails to correctly acquire or release a lock on a shared resource, such as a file, database…
CWE-1232 Sibling
Improper Lock Behavior After Power State Transition
This vulnerability occurs when a hardware lock bit, designed to protect critical system configuration registers, is improperly reset or…
CWE-1233 Sibling
Security-Sensitive Hardware Controls with Missing Lock Bit Protection
This vulnerability occurs when a hardware device uses a lock bit to protect critical configuration registers, but the lock fails to…
CWE-1234 Sibling
Hardware Internal or Debug Modes Allow Override of Locks
Hardware debug modes or internal states can bypass critical system lock protections, allowing unauthorized changes to device configuration.
CWE-412 Sibling
Unrestricted Externally Accessible Lock
This vulnerability occurs when a system correctly checks for a lock's existence, but an unauthorized external actor can control or…
CWE-413 Sibling
Improper Resource Locking
This vulnerability occurs when an application fails to properly lock a shared resource, such as a file or memory location, before…
CWE-414 Sibling
Missing Lock Check
This vulnerability occurs when software fails to verify that a proper synchronization lock is active before accessing or modifying a…
CWE-609 Sibling
Double-Checked Locking
Double-checked locking is an insufficient synchronization pattern where a program checks a resource's state, acquires a lock, and checks…
CWE-764 Sibling
Multiple Locks of a Critical Resource
This vulnerability occurs when a critical resource, such as a file, data structure, or connection, is locked more times than the software…
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.