Vulnerability · Published Nov 25, 2020 · Assigned by GitHub_M
CVE-2020-26241Shallow copy bug in geth
Medium 6.5
In plain English
A medium-severity security flaw in go-ethereum from ethereum. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 69% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Go Ethereum, or "Geth", is the official Golang implementation of the Ethereum protocol. This is a Consensus vulnerability in Geth before version 1.9.17 which can be used to cause a chain-split where vulnerable nodes reject the canonical chain. Geth's pre-compiled dataCopy (at 0x00...04) contract did a shallow copy on invocation. An attacker could deploy a contract that writes X to an EVM memory region R, then calls 0x00..04 with R as an argument, then overwrites R to Y, and finally invokes the RETURNDATACOPY opcode. When this contract is invoked, a consensus-compliant node would push X on the EVM stack, whereas Geth would push Y. This is fixed in version 1.9.17.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/ethereum/go-ethereum | 1.9.17 | GHSA-69v6-xc2j-r2jf |
| Go | github.com/ethereum/go-ethereum | 1.9.17 | GO-2022-0771 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ethereum | go-ethereum | >= 1.9.7, < 1.9.17 |
Weakness: CWE-682 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
References
- https://blog.ethereum.org/2020/11/12/geth_security_release/ x_refsource_MISC
- https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf x_refsource_CONFIRM