soroban-sdk is a Rust SDK for Soroban contracts. Arithmetic overflow can be triggered in the Bytes::slice, Vec::slice, and Prng::gen_range (for u64) methods in the soroban-sdk in versions up to and including 25.0.1, 23.5.1, and 25.0.2. Contracts that pass user-controlled or computed range bounds to Bytes::slice, Vec::slice, or Prng::gen_range may silently operate on incorrect data ranges or generate random numbers from an unintended range, potentially resulting in corrupted contract state.

Note that the best practice when using the soroban-sdk and building Soroban contracts is to always enable overflow-checks = true. The stellar contract init tool that prepares the boiler plate for a Soroban contract, as well as all examples and docs, encourage the use of configuring overflow-checks = true on release profiles so that these arithmetic operations fail rather than silently wrap. Contracts are only impacted if they use overflow-checks = false either explicitly or implicitly.

It is anticipated the majority of contracts could not be impacted because the best practice encouraged by tooling is to enable overflow-checks. The fix available in 25.0.1, 23.5.1, and 25.0.2 replaces bare arithmetic with checked_add / checked_sub, ensuring overflow traps regardless of the overflow-checks profile setting. As a workaround, contract workspaces can be configured with a profile available in the GitHub Securtity Advisory to enable overflow checks on the arithmetic operations.

This is the best practice when developing Soroban contracts, and the default if using the contract boilerplate generated using stellar contract init. Alternatively, contracts can validate range bounds before passing them to slice or gen_range to ensure the conversions cannot overflow.