Segurança

Reinitialization Attack

A vulnerability where a program allows an already-initialized account to be initialized a second time, overwriting its state — including authority or ownership fields — with attacker-supplied data, effectively letting the attacker seize control of an existing account without going through normal privilege checks. The canonical defense is storing an is_initialized boolean or an Anchor discriminator in the account and asserting it is false (or that the discriminator is unset) at the start of every initialization instruction; Anchor's init constraint enforces this by failing if the account's discriminator is already non-zero.

IDreinitialization

Leitura rápida

Comece pela explicação mais curta e útil antes de aprofundar.

A vulnerability where a program allows an already-initialized account to be initialized a second time, overwriting its state — including authority or ownership fields — with attacker-supplied data, effectively letting the attacker seize control of an existing account without going through normal privilege checks. The canonical defense is storing an is_initialized boolean or an Anchor discriminator in the account and asserting it is false (or that the discriminator is unset) at the start of every initialization instruction; Anchor's init constraint enforces this by failing if the account's discriminator is already non-zero.

Modelo mental

Use primeiro a analogia curta para raciocinar melhor sobre o termo quando ele aparecer em código, docs ou prompts.

Pense nisso como um bloco de construção que ajuda a ligar uma definição isolada ao sistema maior onde ela vive.

Contexto técnico

Coloque o termo dentro da camada de Solana em que ele vive para raciocinar melhor sobre ele.

Falhas, auditorias, superfícies de ataque e padrões seguros.

Por que builders ligam para isso

Transforme o termo de vocabulário em algo operacional para produto e engenharia.

Este termo destrava conceitos adjacentes rapidamente, então funciona melhor quando você o trata como um ponto de conexão, não como definição isolada.

Handoff para IA

Handoff para IA

Use este bloco compacto quando quiser dar contexto aterrado para um agente ou assistente sem despejar a página inteira.

Reinitialization Attack (reinitialization)
Categoria: Segurança
Definição: A vulnerability where a program allows an already-initialized account to be initialized a second time, overwriting its state — including authority or ownership fields — with attacker-supplied data, effectively letting the attacker seize control of an existing account without going through normal privilege checks. The canonical defense is storing an is_initialized boolean or an Anchor discriminator in the account and asserting it is false (or that the discriminator is unset) at the start of every initialization instruction; Anchor's init constraint enforces this by failing if the account's discriminator is already non-zero.
Relacionados: Conta, Discriminador
Glossary Copilot

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Explicar este código

Opcional: cole código Anchor, Solana ou Rust para o Copilot mapear primitivas de volta para termos do glossário.

Faça uma pergunta aterrada no glossário

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O Copilot vai responder usando o termo atual, conceitos relacionados, modelos mentais e o grafo ao redor do glossário.

Grafo conceitual

Veja o termo como parte de uma rede, não como uma definição sem saída.

Esses ramos mostram quais conceitos esse termo toca diretamente e o que existe uma camada além deles.

Ramo

Conta

The fundamental data storage unit on Solana. Every piece of state is stored in an account identified by a 32-byte public key. Accounts hold a lamport balance, an owner program, a data byte array (up to 10MB), and an executable flag. Only the owning program can modify an account's data, but anyone can credit lamports to it.

Ramo

Discriminador

An 8-byte identifier prepended to account data and instruction data to distinguish types. Anchor computes it as the first 8 bytes of `sha256('account:<AccountName>')` for accounts and `sha256('global:<function_name>')` for instructions. Discriminators prevent type cosplay attacks by ensuring data is deserialized as the correct type.

Próximos conceitos para explorar

Continue a cadeia de aprendizado em vez de parar em uma única definição.

Estes são os próximos conceitos que valem abrir se você quiser que este termo faça mais sentido dentro de um workflow real de Solana.

Modelo de Programação

Conta

The fundamental data storage unit on Solana. Every piece of state is stored in an account identified by a 32-byte public key. Accounts hold a lamport balance, an owner program, a data byte array (up to 10MB), and an executable flag. Only the owning program can modify an account's data, but anyone can credit lamports to it.

Modelo de Programação

Discriminador

An 8-byte identifier prepended to account data and instruction data to distinguish types. Anchor computes it as the first 8 bytes of `sha256('account:<AccountName>')` for accounts and `sha256('global:<function_name>')` for instructions. Discriminators prevent type cosplay attacks by ensuring data is deserialized as the correct type.

Segurança

Remaining Accounts Misuse

A vulnerability arising from the use of ctx.remaining_accounts in Anchor (or unchecked trailing accounts in native programs), where accounts passed beyond the explicitly declared account struct are not subject to any automatic owner, signer, or constraint checks, leaving it entirely to the program to validate them. Attackers can exploit this by injecting unexpected accounts — fake mints, unauthorized signers, or accounts owned by a malicious program — that the program then treats as trusted inputs. Programs using remaining_accounts must manually verify every account's key, owner, is_signer, and is_writable properties before use, making this pattern a frequent audit finding.

Segurança

Reentrancy Guard

A protective pattern that prevents a program from being invoked recursively through cross-program invocations, mitigating reentrancy attacks. While the Solana runtime inherently prevents direct same-program reentrancy (a program cannot CPI into itself), indirect reentrancy through shared mutable accounts via third-party programs is still possible. Reentrancy guards typically use a flag in account state that is set at instruction entry and cleared at exit, causing reentrant calls to fail. Less critical on Solana than on EVM chains due to the runtime's built-in protection.

Comumente confundido com

Termos próximos em vocabulário, sigla ou vizinhança conceitual.

Essas entradas são fáceis de misturar quando você lê rápido, faz prompting em um LLM ou está entrando em uma nova camada de Solana.

Segurançarevival-attack

Account Revival Attack

An exploit that resurrects an account that a program has logically closed within the same transaction by sending lamports back to it before the transaction finalizes, causing its on-chain data — which was never securely wiped — to re-appear as a funded, seemingly valid account in future transactions. Because the Solana runtime keeps an account alive as long as it holds any lamports, transferring even 1 lamport back to a closed-but-not-wiped account prevents its deletion and allows an attacker to reuse its stale state. The defense is to explicitly overwrite account data with a closed discriminator and to use force-defund patterns so any lamports transferred in during the same transaction are immediately drained.

Segurançaflash-loan-attack

Flash Loan Attack

An exploit where an attacker borrows a large amount of tokens via an uncollateralized flash loan, uses the borrowed funds to manipulate protocol state (typically distorting oracle prices or satisfying collateral requirements), extracts profit from the manipulated state, and repays the loan — all within a single atomic transaction. On Solana, flash loans are possible because transactions are atomic: if any instruction fails, the entire transaction reverts including the loan. Defenses include using time-weighted oracle prices, enforcing borrowing caps, and requiring multi-slot settlement.

Segurançainstruction-ordering-attack

Instruction Ordering Attack

Exploit where an attacker crafts a transaction with instructions in a specific order to manipulate program state between instructions within the same transaction. Since Solana executes all instructions in a transaction sequentially, earlier instructions can modify account state that later instructions depend on, enabling unexpected state transitions.

Termos relacionados

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Entradas de glossário só ficam úteis quando estão conectadas. Esses links são o caminho mais curto para ideias adjacentes.

Modelo de Programaçãoaccount

Conta

The fundamental data storage unit on Solana. Every piece of state is stored in an account identified by a 32-byte public key. Accounts hold a lamport balance, an owner program, a data byte array (up to 10MB), and an executable flag. Only the owning program can modify an account's data, but anyone can credit lamports to it.

Modelo de Programaçãodiscriminator

Discriminador

An 8-byte identifier prepended to account data and instruction data to distinguish types. Anchor computes it as the first 8 bytes of `sha256('account:<AccountName>')` for accounts and `sha256('global:<function_name>')` for instructions. Discriminators prevent type cosplay attacks by ensuring data is deserialized as the correct type.

Mais na categoria

Permaneça na mesma camada e continue construindo contexto.

Essas entradas vivem ao lado do termo atual e ajudam a página a parecer parte de um grafo maior, não um beco sem saída.

Segurança

Missing Signer Check

A vulnerability where a program accepts an account in a privileged role (e.g., admin, authority, payer) without verifying that the account actually signed the transaction, allowing any caller to impersonate that authority by simply passing the target pubkey as an instruction account. In native Solana programs, the check requires asserting account.is_signer == true; in Anchor, the Signer<'info> type enforces this automatically. Exploitation lets an attacker bypass all access control gated on authority equality checks, making it one of the most critical and commonly audited vulnerabilities in Solana programs.

Segurança

Missing Owner Check

A vulnerability where a program deserializes and trusts account data without first confirming that the account is owned by the expected program, allowing an attacker to substitute a maliciously crafted account owned by a different program whose byte layout happens to satisfy the deserialization. On Solana, every account stores a 32-byte owner field set to the program that created it; native programs must assert account.owner == &expected_program_id, while Anchor's Account<'info, T> wrapper performs this check automatically. Failure to validate ownership can lead to complete auth bypass if an attacker can construct a fake account whose data parses into a struct with elevated privileges.

Segurança

Arbitrary CPI

A vulnerability where a program accepts an arbitrary program account from the caller and invokes it via Cross-Program Invocation (CPI) without verifying it matches a known, trusted program ID, effectively letting an attacker substitute a malicious program that executes under the victim program's authority or manipulates accounts the victim program passes to it. A common pattern is accepting a token_program account without checking it equals spl_token::ID, so the attacker passes a lookalike program that records or drains account data. Prevention requires hard-coding or explicitly checking the program ID before every CPI call.

Segurança

PDA Substitution Attack

A vulnerability where a program derives a PDA internally but accepts an externally supplied account as that PDA without re-deriving and comparing the address, allowing an attacker to pass a different PDA (derived from attacker-controlled seeds) that the program will treat as legitimate. Because PDAs are deterministic, the only way to guarantee account identity is to call Pubkey::find_program_address (or equivalent) with the expected seeds inside the program and assert the result equals the supplied key. Anchor's seeds and bump constraints on the Account type automate this re-derivation and equality check.