Vulnerabilities

Bitcoin Core 0.13.0 through 29.x has an integer overflow.

Bitcoin Core through 29.0 allows Uncontrolled Resource Consumption (issue 2 of 2).

Bitcoin Core through 27.2 allows transaction-relay jamming via an off-chain protocol attack, a related issue to CVE-2024-52913. For example, the outcome of an HTLC (Hashed Timelock Contract) can be changed because a flood of transaction traffic prevents propagation of certain Lightning channel transactions.

Bitcoin Core before 24.0.1 allows remote attackers to cause a denial of service (daemon crash) via a flood of low-difficulty header chains (aka a "Chain Width Expansion" attack) because a node does not first verify that a presented chain has enough work before committing to store it.

Bitcoin Core before 25.0 allows remote attackers to cause a denial of service (blocktxn message-handling assertion and node exit) by including transactions in a blocktxn message that are not committed to in a block's merkle root. FillBlock can be called twice for one PartiallyDownloadedBlock instance.

The Miniscript (aka rust-miniscript) library before 12.2.0 for Rust allows stack consumption because it does not properly track tree depth.

In Bitcoin Core through 26.0 and Bitcoin Knots before 25.1.knots20231115, datacarrier size limits can be bypassed by obfuscating data as code (e.g., with OP_FALSE OP_IF), as exploited in the wild by Inscriptions in 2022 and 2023. NOTE: although this is a vulnerability from the perspective of the Bitcoin Knots project, some others consider it "not a bug."

The cryptocurrency wallet entropy seeding mechanism used in Libbitcoin Explorer 3.0.0 through 3.6.0 is weak, aka the Milk Sad issue. The use of an mt19937 Mersenne Twister PRNG restricts the internal entropy to 32 bits regardless of settings. This allows remote attackers to recover any wallet private keys generated from "bx seed" entropy output and steal funds. (Affected users need to move funds to a secure new cryptocurrency wallet.) NOTE: the vendor's position is that there was sufficient documentation advising against "bx seed" but others disagree. NOTE: this was exploited in the wild in June and July 2023.

Memory management and protection issues in Bitcoin Core v22 allows attackers to modify the stored sending address within the app's memory, potentially allowing them to redirect Bitcoin transactions to wallets of their own choosing.

Bitcoin Core before 24.1, when debug mode is not used, allows attackers to cause a denial of service (e.g., CPU consumption) because draining the inventory-to-send queue is inefficient, as exploited in the wild in May 2023.

The Bitcoin / Altcoin Faucet WordPress plugin through 1.6.0 does not have any CSRF check when saving its settings, allowing attacker to make a logged in admin change them via a CSRF attack. Furthermore, due to the lack of sanitisation and escaping, it could also lead to Stored Cross-Site Scripting issues

The Simple Bitcoin Faucets WordPress plugin through 1.7.0 does not have any authorisation and CSRF in an AJAX action, allowing any authenticated users, such as subscribers to call it and add/delete/edit Bonds. Furthermore, due to the lack of sanitisation and escaping, it could also lead to Stored Cross-Site Scripting issues

Bitcoin Core 0.12.0 through 0.21.1 does not properly implement the replacement policy specified in BIP125, which makes it easier for attackers to trigger a loss of funds, or a denial of service attack against downstream projects such as Lightning network nodes. An unconfirmed child transaction with nSequence = 0xff_ff_ff_ff, spending an unconfirmed parent with nSequence <= 0xff_ff_ff_fd, should be replaceable because there is inherited signaling by the child transaction. However, the actual PreChecks implementation does not enforce this. Instead, mempool rejects the replacement attempt of the unconfirmed child transaction.

Bitcoin Core before 0.19.0 might allow remote attackers to execute arbitrary code when another application unsafely passes the -platformpluginpath argument to the bitcoin-qt program, as demonstrated by an x-scheme-handler/bitcoin handler for a .desktop file or a web browser. NOTE: the discoverer states "I believe that this vulnerability cannot actually be exploited."

bitcoind in Bitcoin Core through 0.21.0 can create a new file in an arbitrary directory (e.g., outside the ~/.bitcoin directory) via a dumpwallet RPC call. NOTE: this reportedly does not violate the security model of Bitcoin Core, but can violate the security model of a fork that has implemented dumpwallet restrictions

Bitcoin SV before 0.1.1 allows uncontrolled resource consumption when deserializing transactions.

Bitcoin Core 0.20.0 allows remote denial of service.

Bitcoin Core 0.16.x before 0.16.2 and Bitcoin Knots 0.16.x before 0.16.2 allow remote denial of service via a flood of multiple transaction inv messages with random hashes, aka INVDoS. NOTE: this can also affect other cryptocurrencies, e.g., if they were forked from Bitcoin Core after 2017-11-15.

Abe (aka bitcoin-abe) through 0.7.2, and 0.8pre, allows XSS in __call__ in abe.py because the PATH_INFO environment variable is mishandled during a PageNotFound exception.

Bitcoin Core before 0.14 allows an attacker to create an ostensibly valid SPV proof for a payment to a victim who uses an SPV wallet, even if that payment did not actually occur. Completing the attack would cost more than a million dollars, and is relevant mainly only in situations where an autonomous system relies solely on an SPV proof for transactions of a greater dollar amount.

bitcoind and Bitcoin-Qt prior to 0.15.1 have a stack-based buffer overflow if an attacker-controlled SOCKS proxy server is used. This results from an integer signedness error when the proxy server responds with an acknowledgement of an unexpected target domain name.

In Bitcoin Core 0.18.0, bitcoin-qt stores wallet.dat data unencrypted in memory. Upon a crash, it may dump a core file. If a user were to mishandle a core file, an attacker can reconstruct the user's wallet.dat file, including their private keys, via a grep "6231 0500" command.

Bitcoin Core 0.12.0 through 0.17.1 and Bitcoin Knots 0.12.0 through 0.17.x before 0.17.1.knots20181229 have Incorrect Access Control. Local users can exploit this to steal currency by binding the RPC IPv4 localhost port, and forwarding requests to the IPv6 localhost port.

Bitcoin Core 0.14.x before 0.14.3, 0.15.x before 0.15.2, and 0.16.x before 0.16.3 and Bitcoin Knots 0.14.x through 0.16.x before 0.16.3 allow a remote denial of service (application crash) exploitable by miners via duplicate input. An attacker can make bitcoind or Bitcoin-Qt crash.

An integer overflow in the distributeBTR function of a smart contract implementation for Bitcoin Red (BTCR), an Ethereum ERC20 token, allows the owner to accomplish an unauthorized increase of digital assets by providing a large address[] array, as exploited in the wild in May 2018, aka the "ownerUnderflow" issue.

The mintToken function of a smart contract implementation for BitcoinAgileToken, an Ethereum token, has an integer overflow that allows the owner of the contract to set the balance of an arbitrary user to any value.

In Bitcoin Core before v0.13.0, a non-final alert is able to block the special "final alert" (which is supposed to override all other alerts) because operations occur in the wrong order. This behavior occurs in the remote network alert system (deprecated since Q1 2016). This affects other uses of the codebase, such as Bitcoin Knots before v0.13.0.knots20160814 and many altcoins.

Cross Site Scripting (XSS) exists in PHP Scripts Mall Bitcoin MLM Software 1.0.2 via a profile field.

The Bitcoin Proof-of-Work algorithm does not consider a certain attack methodology related to 80-byte block headers with a variety of initial 64-byte chunks followed by the same 16-byte chunk, multiple candidate root values ending with the same 4 bytes, and calculations involving sqrt numbers. This violates the security assumptions of (1) the choice of input, outside of the dedicated nonce area, fed into the Proof-of-Work function should not change its difficulty to evaluate and (2) every Proof-of-Work function execution should be independent. NOTE: a number of persons feel that this methodology is a benign mining optimization, not a vulnerability

In Bitcoin Knots v0.11.0.ljr20150711 through v0.13.0.knots20160814 (fixed in v0.13.1.knots20161027), the debug console stores sensitive information including private keys and the wallet passphrase in its persistent command history.