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Incorrect Authorization

CVE-2025-46834

Severity Medium
Score 6.6/10

Summary

Alchemy's Modular Account is a smart contract account that is compatible with ERC-4337 and ERC-6900. In versions on the 2.x branch prior to commit 5e6f540d249afcaeaf76ab95517d0359fde883b0, owners of Modular Accounts can grant session keys (scoped external keys) to external parties and would use the allowlist module to restrict which external contracts can be accessed by the session key. There is a bug in the allowlist module in that we don't check for the `executeUserOp` -> `execute` or `executeBatch` path, effectively allowing any session key to bypass any access control restrictions set on the session key. Session keys are able to access ERC20 and ERC721 token contracts amongst others, transferring all tokens from the account out andonfigure the permissions on external modules on session keys. They would be able to remove all restrictions set on themselves this way, or rotate the keys of other keys with higher privileges into keys that they control. Commit 5e6f540d249afcaeaf76ab95517d0359fde883b0 fixes this issue.

  • LOW
  • NETWORK
  • NONE
  • NONE

CWE-863 - Incorrect Authorization

Authorization is a security mechanism performed by an application to grant or deny access to the requested resources by verifying the privileges of the user. When an application lacks effective authorization mechanisms, it enables unauthorized users to gain unintended privileges and illegitimate access to resources. Such a vulnerability may result in exposure of sensitive information, denial of service, arbitrary code execution, and complete system takeover.

References

Advisory Timeline

  • Published