CVEvulnerability

CVE-2020-26241

7.1 HIGH Published 2020-11-25 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-11-25
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS 3.1 ([email protected])
7.1 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
CVSS 2.0 ([email protected])
5.5 MEDIUM — AV:N/AC:L/Au:S/C:N/I:P/A:P
Weaknesses
CWE-682

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 configurations

• ethereum go ethereum (< 1.9.17)

Related

Weakness · CWE (1)

  • CWE-682 Incorrect Calculation weakness

References