Glossary OS

Plain meaning

Start with the shortest useful explanation before going deeper.

A vulnerability where a program retrieves a sysvar (such as Clock, Rent, or SlotHashes) by deserializing an account passed in the instruction's account list rather than using the runtime's native sysvar access API, allowing an attacker to substitute a fake account at the well-known sysvar address with crafted data — for example, a manipulated clock timestamp to bypass time locks. The safe pattern in modern Solana programs is to use Clock::get(), Rent::get(), and equivalent intrinsics that read from the runtime directly without trusting any account; Anchor's Sysvar<'info, Clock> account type validates the address but native programs should prefer the get() API.

Mental model

Use the quick analogy first so the term is easier to reason about when you meet it in code, docs, or prompts.

Think of it as a building block that connects one definition to the larger Solana system around it.

Technical context

Place the term inside its Solana layer so the definition is easier to reason about.

Failure modes, audits, attack surfaces, and safe design patterns.

Why builders care

Turn the term from vocabulary into something operational for product and engineering work.

This term unlocks adjacent concepts quickly, so it works best when you treat it as a junction instead of an isolated definition.

AI handoff

Use this compact block when you want to give an agent or assistant grounded context without dumping the entire page.

Sysvar Spoofing (sysvar-spoofing)
Category: Security
Definition: A vulnerability where a program retrieves a sysvar (such as Clock, Rent, or SlotHashes) by deserializing an account passed in the instruction's account list rather than using the runtime's native sysvar access API, allowing an attacker to substitute a fake account at the well-known sysvar address with crafted data — for example, a manipulated clock timestamp to bypass time locks. The safe pattern in modern Solana programs is to use Clock::get(), Rent::get(), and equivalent intrinsics that read from the runtime directly without trusting any account; Anchor's Sysvar<'info, Clock> account type validates the address but native programs should prefer the get() API.
Related: Sysvar, Clock Sysvar

Glossary Copilot

Ask grounded Solana questions without leaving the glossary.

Use glossary context, relationships, mental models, and builder paths to get structured answers instead of generic chat output.

Open full Copilot workspace

Question

Explain this code

Optional: paste Anchor, Solana, or Rust code so the Copilot can map primitives back to glossary terms.

Ask a glossary-grounded question

The Copilot will answer using the current term, related concepts, mental models, and the surrounding glossary graph.

Concept graph

See the term as part of a network, not a dead-end definition.

These branches show which concepts this term touches directly and what sits one layer beyond them.

Branch

Sysvar

Special read-only accounts maintained by the runtime that expose cluster state to programs. Key sysvars include Clock (slot, timestamp), Rent (lamports-per-byte), EpochSchedule (epoch parameters), RecentBlockhashes, StakeHistory, and Fees. Programs access sysvars by including the sysvar account in the instruction or via the sol_get_sysvar syscall.

Rent Exemption Epoch Schedule

Open term

Branch

Clock Sysvar

A sysvar (address: SysvarC1ock11111111111111111111111111111111) that provides the current slot, epoch, unix_timestamp, and leader_schedule_epoch. Programs use Clock to implement time-based logic like lockups or vesting schedules. In Anchor, accessed via `Clock::get()` or as a sysvar account in the accounts struct.

Slot Epoch

Open term

Next concepts to explore

Keep the learning chain moving instead of stopping at one definition.

These are the next concepts worth opening if you want this term to make more sense inside a real Solana workflow.

Programming Model

Sysvar

Special read-only accounts maintained by the runtime that expose cluster state to programs. Key sysvars include Clock (slot, timestamp), Rent (lamports-per-byte), EpochSchedule (epoch parameters), RecentBlockhashes, StakeHistory, and Fees. Programs access sysvars by including the sysvar account in the instruction or via the sol_get_sysvar syscall.

Open term

Programming Model

Clock Sysvar

A sysvar (address: SysvarC1ock11111111111111111111111111111111) that provides the current slot, epoch, unix_timestamp, and leader_schedule_epoch. Programs use Clock to implement time-based logic like lockups or vesting schedules. In Anchor, accessed via `Clock::get()` or as a sysvar account in the accounts struct.

Open term

Security

Time-Lock

A security mechanism that enforces a mandatory delay between proposing a privileged action (such as a program upgrade, treasury withdrawal, or parameter change) and its execution. Time-locks give stakeholders and users a window to review pending actions, detect malicious proposals, and exit the protocol if needed. On Solana, time-locks are typically implemented through multisig programs like Squads or governance frameworks that queue transactions for a configurable delay period before they become executable.

Open term

Security

Stateful Fuzzing

An advanced fuzzing technique that maintains program state across iterations, generating sequences of instructions rather than individual random inputs. Stateful fuzzing can discover vulnerabilities that only manifest after specific sequences of operations, such as a withdraw-after-close or a double-init attack. Trident implements stateful fuzzing for Solana programs by maintaining a simulated runtime state and generating random instruction sequences with valid account configurations derived from the program's Anchor IDL.

Open term

Related terms

Follow the concepts that give this term its actual context.

Glossary entries become useful when they are connected. These links are the shortest path to adjacent ideas.

Programming Modelsysvar

Sysvar

Special read-only accounts maintained by the runtime that expose cluster state to programs. Key sysvars include Clock (slot, timestamp), Rent (lamports-per-byte), EpochSchedule (epoch parameters), RecentBlockhashes, StakeHistory, and Fees. Programs access sysvars by including the sysvar account in the instruction or via the sol_get_sysvar syscall.

Open term

Programming Modelclock

Clock Sysvar

A sysvar (address: SysvarC1ock11111111111111111111111111111111) that provides the current slot, epoch, unix_timestamp, and leader_schedule_epoch. Programs use Clock to implement time-based logic like lockups or vesting schedules. In Anchor, accessed via `Clock::get()` or as a sysvar account in the accounts struct.

Open term

Stay in the same layer and keep building context.

These entries live beside the current term and help the page feel like part of a larger knowledge graph instead of a dead end.

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