CVE-2020-26241
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
- EPSS
- 1.09% probability · 64th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-682
- Affected
- ethereum/go ethereum
- Source
- security-advisories@github.com
References
- https://blog.ethereum.org/2020/11/12/geth_security_release/Vendor Advisory
- https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jfThird Party Advisory
- https://blog.ethereum.org/2020/11/12/geth_security_release/Vendor Advisory
- https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jfThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.