CVE-2018-20421
Go Ethereum (aka geth) 1.8.19 allows attackers to cause a denial of service (memory consumption) by rewriting the length of a dynamic array in memory, and then writing data to a single memory location with a large index number, as demonstrated by use of…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Go Ethereum (aka geth) 1.8.19 allows attackers to cause a denial of service (memory consumption) by rewriting the length of a dynamic array in memory, and then writing data to a single memory location with a large index number, as demonstrated by use of "assembly { mstore }" followed by a "c[0xC800000] = 0xFF" assignment.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.46% probability · 73th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- ethereum/go ethereum
- Source
- cve@mitre.org
EPSS 1.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/ethereum/go-ethereum/issues/18289Exploit, Third Party Advisory
- https://github.com/ethereum/go-ethereum/issues/18289Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.