Bitcoin : Security Vulnerabilities, CVEs, CVSS score >= 6

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.

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 Core 0.20.0 allows remote denial of service.

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 0.16.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.

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.

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.

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 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.

Bitcoin Core before v0.13.0 allows denial of service (memory exhaustion) triggered by the remote network alert system (deprecated since Q1 2016) if an attacker can sign a message with a certain private key that had been known by unintended actors, because of an infinitely sized map. This affects other uses of the codebase, such as Bitcoin Knots before v0.13.0.knots20160814 and many altcoins.

bitcoind and Bitcoin-Qt prior to 0.10.2 allow attackers to cause a denial of service (disabled functionality such as a client application crash) via an "Easy" attack.

bitcoind and Bitcoin-Qt before 0.4.9rc2, 0.5.x before 0.5.8rc2, 0.6.x before 0.6.5rc2, and 0.7.x before 0.7.3rc2, and wxBitcoin, do not properly consider whether a block's size could require an excessive number of database locks, which allows remote attackers to cause a denial of service (split) and enable certain double-spending capabilities via a large block that triggers incorrect Berkeley DB locking.

bitcoind and Bitcoin-Qt 0.8.0 and earlier allow remote attackers to cause a denial of service (electricity consumption) by mining a block to create a nonstandard Bitcoin transaction containing multiple OP_CHECKSIG script opcodes.

The alert functionality in bitcoind and Bitcoin-Qt before 0.7.0 supports different character representations of the same signature data, but relies on a hash of this signature, which allows remote attackers to cause a denial of service (resource consumption) via a valid modified signature for a circulating alert.

Bitcoin-Qt 0.5.0.x before 0.5.0.5; 0.5.1.x, 0.5.2.x, and 0.5.3.x before 0.5.3.1; and 0.6.x before 0.6.0rc4 on Windows does not use MinGW multithread-safe exception handling, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via crafted Bitcoin protocol messages.

wxBitcoin and bitcoind before 0.3.5 do not properly handle script opcodes in Bitcoin transactions, which allows remote attackers to spend bitcoins owned by other users via unspecified vectors.

Integer overflow in wxBitcoin and bitcoind before 0.3.11 allows remote attackers to bypass intended economic restrictions and create many bitcoins via a crafted Bitcoin transaction.