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A family of Rust arithmetic methods — including checked_add, checked_sub, checked_mul, checked_div, and their saturating_* counterparts — that return an Option<T> (None on overflow/underflow) instead of silently wrapping, allowing Solana programs to propagate an error rather than continue with corrupted values. Because Rust's default integer arithmetic panics on overflow only in debug builds and wraps silently in release builds (the mode used for on-chain deployments), all financial and security-sensitive arithmetic in Solana programs should use these methods. Anchor's declare_program! macro and many audit checklists explicitly require checked math on all token amount calculations.

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Checked Math (checked-math)
Category: Security
Definition: A family of Rust arithmetic methods — including checked_add, checked_sub, checked_mul, checked_div, and their saturating_* counterparts — that return an Option<T> (None on overflow/underflow) instead of silently wrapping, allowing Solana programs to propagate an error rather than continue with corrupted values. Because Rust's default integer arithmetic panics on overflow only in debug builds and wraps silently in release builds (the mode used for on-chain deployments), all financial and security-sensitive arithmetic in Solana programs should use these methods. Anchor's declare_program! macro and many audit checklists explicitly require checked math on all token amount calculations.
Related: Integer Overflow / Underflow

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Integer Overflow / Underflow

A class of arithmetic vulnerabilities where an integer computation produces a result outside the bounds of its fixed-width type, wrapping around silently in Rust's release builds (since Rust panics on overflow only in debug mode), yielding an incorrect value that can corrupt token balances, borrow limits, or access control counters. For example, subtracting a larger u64 from a smaller one wraps to near u64::MAX (~1.8 × 10^19), which could be interpreted as an enormous balance. Solana programs must use Rust's checked_add, checked_sub, checked_mul, and checked_div methods (or the saturating_* / wrapping_* variants with deliberate intent) on all financial arithmetic to eliminate this class of bugs.

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Security

Integer Overflow / Underflow

A class of arithmetic vulnerabilities where an integer computation produces a result outside the bounds of its fixed-width type, wrapping around silently in Rust's release builds (since Rust panics on overflow only in debug mode), yielding an incorrect value that can corrupt token balances, borrow limits, or access control counters. For example, subtracting a larger u64 from a smaller one wraps to near u64::MAX (~1.8 × 10^19), which could be interpreted as an enormous balance. Solana programs must use Rust's checked_add, checked_sub, checked_mul, and checked_div methods (or the saturating_* / wrapping_* variants with deliberate intent) on all financial arithmetic to eliminate this class of bugs.

Open term

Security

Closing Accounts Vulnerability

A vulnerability that arises when a program closes an account by zeroing its data and transferring lamports without setting the account's discriminator or data to a sentinel closed state before the end of the instruction, leaving a window within the same transaction where other instructions can still interact with the now-empty account. The Solana runtime only removes an account from the account set when its lamports reach zero at the end of a transaction, so mid-transaction the account still exists and a subsequent instruction can re-fund it and reinstate stale data, enabling an account revival attack. Anchor's close constraint writes a CLOSED_ACCOUNT_DISCRIMINATOR (8 bytes of 0xff) and uses a force-defund mechanism to prevent resurrection.

Open term

Security

Bump Seed Canonicalization

The requirement that, when deriving a Program Derived Address (PDA), a program always use the canonical bump — the highest bump value (starting from 255 and decrementing) for which find_program_address returns a valid off-curve point — rather than accepting an arbitrary bump supplied by the caller. If a program stores and re-uses a non-canonical bump, an attacker can create a different PDA (with a different canonical bump) that happens to match a seed set the program trusts, or can derive valid PDAs outside the expected namespace. Anchor's seeds and bump constraints enforce canonicalization by calling find_program_address internally and asserting the provided bump matches; storing the canonical bump in the account at init time (instead of rediscovering it) is the recommended gas-efficient pattern.

Open term

Security

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.

Open term

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Securityinteger-overflow

Integer Overflow / Underflow

A class of arithmetic vulnerabilities where an integer computation produces a result outside the bounds of its fixed-width type, wrapping around silently in Rust's release builds (since Rust panics on overflow only in debug mode), yielding an incorrect value that can corrupt token balances, borrow limits, or access control counters. For example, subtracting a larger u64 from a smaller one wraps to near u64::MAX (~1.8 × 10^19), which could be interpreted as an enormous balance. Solana programs must use Rust's checked_add, checked_sub, checked_mul, and checked_div methods (or the saturating_* / wrapping_* variants with deliberate intent) on all financial arithmetic to eliminate this class of bugs.

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Security

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.

Open term

Security

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.

Open term

Security

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.

Open term

Security

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.

Open term