# Security Alert - DoS Vulnerability in the Soft Fork

DevFeed: [Security Alert - DoS Vulnerability in the Soft Fork](<https://devfeed.tech/articles/security-alert-dos-vulnerability-in-the-soft-fork-16768.md>)

Original publisher: [Read original article](<https://blog.ethereum.org/en/2016/06/28/security-alert-dos-vulnerability-in-the-soft-fork>)

Author: Felix Lange

Published: 2016-06-28T18:21:40Z

Content type: article

Language: en

Sources: [Ethereum Foundation Blog](<https://devfeed.tech/sources/ethereum-foundation-blog.md>)

Topics: [Security](<https://devfeed.tech/topics/security.md>), [vulnerability](<https://devfeed.tech/topics/vulnerability.md>), [Exploit](<https://devfeed.tech/topics/exploit.md>), [Code](<https://devfeed.tech/topics/code.md>), [Transactions](<https://devfeed.tech/topics/transactions.md>)

Tags: [code](<https://devfeed.tech/tags/code.md>), [command-line](<https://devfeed.tech/tags/command-line.md>), [fork](<https://devfeed.tech/tags/fork.md>), [security](<https://devfeed.tech/tags/security.md>), [transactions](<https://devfeed.tech/tags/transactions.md>), [vulnerability](<https://devfeed.tech/tags/vulnerability.md>)

## AI overview

A security alert describes a high-severity, high-likelihood denial-of-service attack vector in the DAO soft fork implementation used by geth 1.4.8 and other clients. The fork code can execute EVM code up to the block gas limit without charging gas, potentially slowing mining and preventing legitimate transactions from being included. Suggested temporary workarounds are to use geth 1.4.7 or run geth 1.4.8 without the --dao-soft-fork option.

## Source excerpt

Affected configurations: geth 1.4.8 Likelihood: High Severity: High Details: An attack vector has been identified in the freshly released implementation of the DAO soft fork. The fork enactment code in geth (and other clients) allows execution of EVM code up to the block gas limit without paying for...