CVE-2020-26241

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

25/11/2020

Last modified:

03/12/2020

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&#39;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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L CVSS v3.1 Severity and Metrics:

Base Score: 7.10 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): High
Availability (A): Low

Base Score 3.x

7.10

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:L/Au:S/C:N/I:P/A:P CVSS v2.0 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: AV:N/AC:L/Au:S/C:N/I:P/A:P

Attack Vector (AV): Network
Attack Complexity (AC): Low
Authentication (Au): Single
Confidentiality (C): None
Integrity (I): Physical
Availability (A): Physical