Divide by Zero Detonation Attack

“A Divide by Zero Detonation attack is a denial of service attack that targets a vulnerability in Bitcoin Core’s Bloom filter. An attacker sends a malicious zero-size filter, causing division by zero during data processing. This results in the immediate crash of a node, rendering it inoperable and disrupting the availability of the entire network.” cvedetails+4

The Divide by Zero Detonation attack is a prime example of how a subtle implementation detail can lead to serious vulnerabilities in critical infrastructure. Timely analysis, strict boundary checking, and protection at every stage of user parameter handling are key to the ongoing security of large cryptocurrency systems.

The Divide by Zero Detonation attack (CVE-2013-5700) demonstrated that even a low-level arithmetic error can have critical consequences for a decentralized infrastructure. It opened a new class of threats, known as Arithmetic State Vulnerabilities .

From a cryptographic analysis perspective, such attacks do not violate encryption, but rather the cryptographic strength of the infrastructure trust . Therefore, multi-layered auditing of secure computing boundaries is necessary in the future, especially in platforms with open protocols like Bitcoin.

The Divide by Zero Detonation attack (CVE-2013-5700) became a striking example of how a single arithmetic error can turn into a systemic threat to the entire cryptocurrency ecosystem. A seemingly benign division-by-zero exception in Bitcoin Core’s Bloom filter implementation turned into a strategic vulnerability, developing into a critical denial-of-service (RDS) vector. This vulnerability allowed an attacker to use a single specially crafted network packet to shut down a Bitcoin node, effectively deactivating its participation in consensus.

Characteristic signs

Instant deactivation of a node via crafted message
Using a Mathematical Trap for DoS
Network availability explosion based on the “detonation” principle at a critical data processing point
The attack is easily recognized, remembered by name, and reflects the essence of a bug that instantly “explodes” a service by dividing by zero.

Formal technical specification

Exploiting CVE-2013-5700 via a crafted bloom filter message
Calling a procedure that implements division by zero:MurmurHash3(...) % (vData.size() * 8)
Sudden Crash and Denial of Service

Divide by Zero Detonation: A critical arithmetic attack (CVE-2013-5700) on the Bitcoin cryptocurrency infrastructure, threatening the availability and stability of the network.

Divide by Zero Detonation: A Scientific Analysis of the Critical Vulnerability CVE-2013-5700 and Its Cryptographic Impact on the Bitcoin Network

Annotation

This article provides an in-depth scientific analysis of the CVE-2013-5700 vulnerability discovered in the Bitcoin Core Bloom filter implementation . This division-by-zero bug allowed an attacker to cause a remote denial-of-service (RDS) via specially crafted messages. We examine the activation mechanisms, the impact on the stability of the decentralized Bitcoin network, the attack classification, and propose systemic mitigations against similar vulnerabilities in the future.

1. Introduction

Bloom filters in Bitcoin Core (versions 0.8.x and earlier, 0.8.4rc1) were used to select relevant transactions when running SPV clients. They were generated and transmitted between nodes via the P2P protocol in messages filterloadand filteradd. A critical flaw was discovered in the handler of these messages: the ability to create a filter of zero size , which led to a division by zero and a node crash. nvd.nist+ 2

2. The mechanism of vulnerability occurrence

The error was due to a missing parameter check vData.size()in the Bloom filter element hashing function:

cppreturn MurmurHash3(nHashNum * 0xFBA4C795 + nTweak, vDataToHash) % (vData.size() * 8);

If the filter size is zero, the operation % (vData.size() * 8)causes division by zero , which immediately terminates the process. Thus, an attacker could construct a syntactically correct but logically invalid P2P message with a zero-length parameter and crash a remote Bitcoin Core node. access.redhat+ 1

3. Scientific classification of attack

This vulnerability has the number CVE-2013-5700 and is officially classified in the NIST and CVE registries as Denial-of-Service (Divide-by-Zero Error in Bloom Filter) . cve+2 From
a scientific perspective, the attack type is described as:

Remote Arithmetic State Disruption Attack (RASD)
or, in the research terminology used,
Divide by Zero Detonation Attack .

This name reflects the nature of the impact: manipulation of the arithmetic state of an application to generate a crash condition and subsequent denial of service.

4. Impact on Bitcoin infrastructure

4.1 Network-level effects

The node stops relaying transactions , causing a temporary disconnection from the network.
Local delays in block propagation appear as SPV nodes lose connections. bitcoincore+ 1
Scalable attack : When repeated in large numbers, it can temporarily weaken network throughput and destabilize Light client nodes.

4.2 Effects on the level of trust

Decreasing node availability increases the imbalance between miners and SPV clients.
The ability to prepare temporary consensus divergences during forced stops of certain nodes.
Theoretically, temporary network “gaps” could be used as a precursor to Eclipse attacks . usenix+ 1

5. Clarification of the cryptographic nature

Although the vulnerability does not involve leaking private keys, its impact is directly related to the cryptographic principles of system integrity. A daemon crash violates network consensus invariants and can temporarily weaken the guarantee of immutability of blockchain data.

Thus, Divide by Zero Detonation can be seen as a cryptographic integrity failure , undermining the availability guarantee underlying decentralized trust.

6. Vulnerability fix and secure solution

Bitcoin Core 0.8.4rc1 and later completely fixed the bug, adding filter size checks and a secure processing mechanism:

cppvoid CBloomFilter::insert(std::span<const unsigned char> vKey) {
    // Предотвращаем деление на ноль (CVE-2013-5700)
    if (vData.empty()) 
        return; // безопасное завершение без обращения к пустому фильтру
    
    for (unsigned int i = 0; i < nHashFuncs; i++) {
        unsigned int nIndex = Hash(i, vKey);
        vData[nIndex >> 3] |= (1 << (7 & nIndex));
    }
}

This approach prevents all subsequent potential DoS vectors by completely eliminating situations in which the hashing operation could be performed with zero size.

Additional measures

Validation of parameters at the network API level ( filterload, merkleblock).
Introducing limits on the minimum size of a Bloom filter in the core code.
Logging attempts to create filters with zero size as indicators of attack.
Isolation of peer sessions when such attempts are detected (sandbox isolation).

7. Conclusion

Bitcoin Core Bloom Filter Cryptographic Vulnerability

After a thorough analysis of the provided Bitcoin Core code related to Bloom filters, I discovered one critical vulnerability, CVE-2013-5700 . bitcoincore+ 2

Location of vulnerability

Line 40 contains the main vulnerability:

cpp:

return MurmurHash3(nHashNum * 0xFBA4C795 + nTweak, vDataToHash) % (vData.size() * 8);

Description of the vulnerability

CVE-2013-5700 : Nvd.nist+ 1 Divide-by-Zero Vulnerability

Type : Denial of Service (DoS)
Reason : If the Bloom filter size is zero ( vData.size() == 0), the expression (vData.size() * 8)becomes zero, which results in a division by zero when performing the modulo operation.
Impact : Remote Crash of a Bitcoin Node

https://github.com/keyhunters/bitcoin/blob/master/src/common/bloom.cpp

Code fixes

The code contains security checks that were added to fix this vulnerability:

Lines 47-48 (function insert):

cpp:

if (vData.empty()) // Avoid divide-by-zero (CVE-2013-5700)
    return;

Lines 59-60 (function contains):

cpp:

if (vData.empty()) // Avoid divide-by-zero (CVE-2013-5700)
    return true;

The technical essence of the attack

An attacker could send a message filterloadwith a filter size of zero, resulting in the creation of an empty Bloom filter. Subsequent operations on this filter (for example, when checking elements) would result in division by zero in the function Hash(), causing the bitcoind or Bitcoin-Qt process to crash. bitcoincore+ 2

Important clarification

This is a denial of service vulnerability that allows a Bitcoin node to be shut down remotely, but does not compromise cryptographic keys or user funds. pages.mtu+ 1

This issue was fixed in Bitcoin Core version 0.8.4rc1 in September 2013. Bloom filters in Bitcoin were used to improve the privacy of SPV clients, but were later found to be problematic from a privacy standpoint. blockchain-academy.hs-mittweida+2

No.*

Divide by Zero Detonation: Bitcoin Bloom Filter Vulnerability Research and Security Techniques

Annotation

This article presents a thorough analysis of the Divide by Zero Detonation vulnerability discovered in the Bloom filter module of Bitcoin Core and its impact on the security of network nodes. We will examine the causes of this vulnerability, walk through its exploitation mechanisms, and propose a modern, secure solution to mitigate and prevent similar attacks in the future.

1. Introduction

Bloom filters are widely used in Bitcoin Core to improve privacy and speed up transaction lookups in SPV client mode. However, improper handling of edge-case scenarios (such as a zero-size filter) leads to logical denial-of-service (DoS) vulnerabilities.

2. The essence of the Divide by Zero Detonation vulnerability

A Bloom filter is initialized with a specific size (vector vData), the number of bits determined by user settings or an incoming network message. When creating a filter, it is critical to ensure that its size is not zero.

Problematic fragment

cppinline unsigned int CBloomFilter::Hash(unsigned int nHashNum, std::span<const unsigned char> vDataToHash) const {
    // ...
    return MurmurHash3(nHashNum * 0xFBA4C795 + nTweak, vDataToHash) % (vData.size() * 8); 
}

There was no null check in this section of code vData.size().

If the filter is empty, division by zero occurs.
This causes the bitcoind process or client to crash with a fatal error.
An attacker can send a specially crafted message to initiate this failure on any node in the network (DoS).

3. Consequences and risks

Remote DoS : Critical denial of service over the network, accessible without authentication.
Reduced reliability : A massive attack may result in partial unavailability of large pools or nodes.
Privacy : Although the confidentiality of keys is not affected, an attacker can affect the operation of light clients or perform a rotation attack.

4. Best methods of correction

Principles

Never perform mathematical operations on arguments whose size is not checked for zero.
Perform a strict check on the size of the filter and the hashed object BEFORE accessing the resource.
Always return the correct behavior for edge-case scenarios (e.g. match-all or match-none for an empty filter).

Secure patched code

cppinline unsigned int CBloomFilter::Hash(unsigned int nHashNum, std::span<const unsigned char> vDataToHash) const {
    // Безопасная версия: проверяем размер
    if (vData.size() == 0) {
        // Можно выбросить исключение/вернуть фиксированное значение или использовать альтернативную логику
        throw std::runtime_error("Bloom filter size is zero (attack attempt detected)");
        // Либо return 0 / return UINT_MAX, если это допустимо в архитектуре
    }
    return MurmurHash3(nHashNum * 0xFBA4C795 + nTweak, vDataToHash) % (vData.size() * 8);
}

// В местах использования — строгий early exit:
void CBloomFilter::insert(std::span<const unsigned char> vKey) {
    if (vData.empty()) // Предотвращаем атаку и ошибку деления
        return;
    // остальной код
}

Best practices

Fail Fast : Validate parameters when initializing/creating an object and immediately terminate execution or take corrective action on invalid input.
Invariants : Ensure that during the lifetime of a Bloom Filter object, its size is never zero (set a default minimum size).
Attack logging : Log attempts to create a zero-size filter as a possible attack attempt and implement IP blacklists.
Unified Parameter Validators : Perform centralized validation across the network interaction layers, filtering out invalid messages before passing them to the Bloom filter logic.

5. General recommendations for repelling similar attacks

Use error-tolerant design patterns (Design by Contract).
Instrument and automate edge case checks during integration testing.
Make adjustments to all code paths that use a size calculated from external or user input.

6. Conclusion

This robust verification mechanism and fault-tolerant pattern ensures that such a vulnerability cannot reoccur, even if the Bloom filter architecture or its parameters change in the future.

Final scientific conclusion

From a cryptographic perspective, this flaw didn’t destroy the protocol’s mathematical foundations, but it did undermine trust and availability , which together form part of the DAD (Decentralization, Availability, and Decency) security triad. The Divide by Zero Detonation vulnerability transformed nodes into isolated links capable of partially destroying the network topology, weakening transaction flow, and causing temporary divergences in the blockchain. In a distributed architecture, even short-term node failures create the conditions for network fragmentation, which can be exploited in hybrid attacks such as Partitioning or Eclipse , paving the way for double-spending and mempool manipulation.

The scientific and engineering significance of the incident lies in the fact that arithmetic security becomes a cryptographic aspect : a violation of elementary numerical invariants in code can destabilize a system based on mathematical consensus. Therefore, protection against such vulnerabilities requires not only cryptographic analysis but also strict control over the arithmetic integrity of calculations.

The fix implemented in Bitcoin Core 0.8.4rc1 not only eliminated division by zero but also became an example of the transition from reactive to proactive security , where logical data boundaries are protected at the API level. This established a new standard for the development of critical modules in cryptocurrency systems: every operation that potentially leads to an exception must be considered a cryptographic threat.

As a result, Divide by Zero Detonation became the first documented arithmetic attack on Bitcoin’s architecture , officially registered under the number CVE-2013-5700 . Its existence served as a reminder that the security of digital currencies is determined not only by the resistance to key cracking, but also by the correctness of every bit expression involved in the trust calculation.

CVE ID: CVE-2013-5700
Scientific name of the attack: Divide by Zero Detonation (Remote Arithmetic State Disruption Attack)
Classification: Remote Denial-of-Service (Arithmetic Logic Exception)
Fix implemented: Bitcoin Core version 0.8.4rc1. vulmon+ 3

By

Divide by Zero Detonation Attack

Characteristic signs

Formal technical specification

Divide by Zero Detonation: A Scientific Analysis of the Critical Vulnerability CVE-2013-5700 and Its Cryptographic Impact on the Bitcoin Network

Annotation

1. Introduction

2. The mechanism of vulnerability occurrence

3. Scientific classification of attack

4. Impact on Bitcoin infrastructure

4.1 Network-level effects

4.2 Effects on the level of trust

5. Clarification of the cryptographic nature

6. Vulnerability fix and secure solution

Additional measures

7. Conclusion

Location of vulnerability

Code fixes

The technical essence of the attack

Important clarification

Divide by Zero Detonation: Bitcoin Bloom Filter Vulnerability Research and Security Techniques

Annotation

1. Introduction

2. The essence of the Divide by Zero Detonation vulnerability

Problematic fragment

3. Consequences and risks

4. Best methods of correction

Principles

Secure patched code

Best practices

5. General recommendations for repelling similar attacks

6. Conclusion

Final scientific conclusion

By

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