OpenZeppelin Contracts initializer reentrancy may lead to double initialization
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 4.4.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
OpenZeppelin Contracts is a library for secure smart contract development. Before version 4.4.1 but after 3.2.0, initializer functions that are invoked separate from contract creation (the most prominent example being minimal proxies) may be reentered if they make an untrusted non-view external call. Once an initializer has finished running it can never be re-executed. However, an exception put in place to support multiple inheritance made reentrancy possible in the scenario described above, breaking the expectation that there is a single execution. Note that upgradeable proxies are commonly initialized together with contract creation, where reentrancy is not feasible, so the impact of this issue is believed to be minor. This issue has been patched, please upgrade to version 4.4.1. As a workaround, avoid untrusted external calls during initialization.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- OpenZeppelin openzeppelin-contracts
From 3.2.0 · fixed in 4.4.1
- @openzeppelin/contractsnpm
From 3.2.0 · fixed in 4.4.1
- @openzeppelin/contracts-upgradeablenpm
From 3.2.0 · fixed in 4.4.1
- @openzeppelin/contractsnpm
fixed in 4.4.1