| CVE-2020-26241 | Date: (C)2020-11-25 (M)2023-12-22 |
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 Score and Metrics +CVSS Score and Metrics -| CVSS V3 Severity: | CVSS V2 Severity: |
| CVSS Score : 7.1 | CVSS Score : 5.5 |
| Exploit Score: 2.8 | Exploit Score: 8.0 |
| Impact Score: 4.2 | Impact Score: 4.9 |
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| CVSS V3 Metrics: | CVSS V2 Metrics: |
| Attack Vector: NETWORK | Access Vector: NETWORK |
| Attack Complexity: LOW | Access Complexity: LOW |
| Privileges Required: LOW | Authentication: SINGLE |
| User Interaction: NONE | Confidentiality: NONE |
| Scope: UNCHANGED | Integrity: PARTIAL |
| Confidentiality: NONE | Availability: PARTIAL |
| Integrity: HIGH | |
| Availability: LOW | |
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