CWE-833 Deadlock

Description

Deadlock

Reference: https://cwe.mitre.org/data/definitions/833.html

OWASP Category: A04:2021 – Insecure Design

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Vulnerable Pattern

❌ Example 1: Vulnerable Pattern

// VULNERABLE: Potential deadlock - different lock ordering
public void transferMoney(Account from, Account to, int amount) {
    synchronized (from) {
        synchronized (to) {
            from.withdraw(amount);
            to.deposit(amount);
        }
    }
}

Why it's vulnerable: This pattern is vulnerable to Deadlock

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Deterministic Fix

✅ Secure Implementation: Secure Implementation

// SECURE: Consistent lock ordering
public void transferMoney(Account from, Account to, int amount) {
    Account first = from.getId() < to.getId() ? from : to;
    Account second = from.getId() < to.getId() ? to : from;

    synchronized (first) {
        synchronized (second) {
            from.withdraw(amount);
            to.deposit(amount);
        }
    }
}

Why it's secure: Implements proper protection against Deadlock

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Detection Pattern

Look for these patterns in your codebase:

# Find nested synchronized
grep -rn "synchronized.*{" --include="*.java" -A10 | grep "synchronized"

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Remediation Steps

1. Always acquire locks in consistent order

2. Use Lock.tryLock() with timeout

3. Consider lock-free data structures

4. Use higher-level concurrency utilities

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Key Imports

import java.util.concurrent.locks.Lock;

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Verification

After remediation:

• Run SAST scanner to confirm vulnerability is resolved

• Review all instances of the vulnerable pattern

• Add unit tests that verify the secure implementation

• Check for similar patterns in related code

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Trigger Examples

Fix CWE-833 vulnerability
Resolve Deadlock issue
Secure this Java code against deadlock
SAST reports CWE-833

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Common Vulnerable Locations

Layer	Files	Patterns

| Controller | *Controller.java | User input handling |

| Service | *Service.java | Business logic |

| Repository | *Repository.java | Data access |

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References

• CWE-833: Deadlock

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Source: Generated by Java CWE Security Skills Generator Last Updated: 2026-03-07