Vulnerability in Ethereum Go-Ethereum
CVE-2020-26241
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.
EPSS: 0.011 (61.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Ethereum Go-ethereum — versions >= 1.9.7, < 1.9.17
- Ethereum Go_ethereum
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_MISC, Vendor Advisory)
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-26241?
- CVE-2020-26241 is a medium-severity vulnerability in Ethereum Go-Ethereum, classified under Incorrect Calculation. CVSS score: 6.5/10. Published 2020-11-25.
- How severe is CVE-2020-26241?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2020-26241 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.