Geth security release | Ethereum Foundation Blog

Abstract

Variations of geth constructed with Go or are most probably affected by a important DoS-related safety vulnerability. The golang group has registered this flaw as ‘CVE-2020-28362’.

We advocate all customers to rebuild (ideally v1.9.24) with Go 1.15.5 or 1.14.12, to keep away from node crashes. Alternatively, if you’re operating binaries distributed through one among our official channels, we’ll launch v1.9.24 ourselves constructed with Go 1.15.5.

Docker photos will most likely be outdated resulting from a lacking base picture, however you’ll be able to test the discharge notes on how one can quickly construct one with Go 1.15.5. Please run geth model to confirm the Go model your binary was constructed with.

Background

In early October, go-ethereum enrolled into Google’s OSS-Fuzz program. We had previosly executed fuzzers on an ad-hoc foundation and examined some totally different platforms.

On 2020-10-24, we have been notified that one among our fuzzers had discovered a crash.

Upon investigation, it turned out that the basis reason for the difficulty was a bug in the usual libraries of Go, and the difficulty was reported upstream.

Particular due to Adam Korczynski of Ada Logics for the preliminary integration of go-ethereum into OSS-Fuzz!

Impression

The DoS difficulty can be utilized to crash all Geth nodes throughout block processing, the consequences of which might be {that a} main a part of the Ethereum community went offline.

Outdoors of Go-Ethereum, the difficulty is most probably related for all forks of Geth (reminiscent of TurboGeth or ETC’s core-geth). For a good wider context, we might discuss with upstream, because the Go-team have carried out an investigation of probably affected events.

Timeline

• 2020-10-24: Crash report from OSS-fuzz
• 2020-10-25: Investigation discovered that it was resulting from flaw in Go. Particulars despatched to security@golang.org
• 2020-10-26: Acknowledgement from upstream, investigation ongoing
• 2020-10-26 — 2020-11-06: Potential fixes mentioned, upstream investigation of probably affected events
• 2020-11-06: Upstream tentatively scheduled fix-release for 2020-11-12
• 2020-11-09: Upstream pre-announced the safety launch: https://groups.google.com/g/golang-announce/c/kMa3eup0qhU/m/O5RSMHO_CAAJ
• 2020-11-11: Notified customers concerning the upcoming launch through the official Geth twitter account, our official Discord-channel and Reddit.
• 2020-11-12: New Go model have been launched, and new geth binaries have been launched

Further points

Mining flaw

One other safety difficulty was delivered to our consideration through this PR, containing a repair to the ethash algorithm.

The mining flaw may trigger miners to erroneously calculate PoW in an upcoming epoch. This occurred on the ETC chain on 2020-11-06. It seems that this is able to be a problem for ETH mainnet round block 11550000 / epoch 385, which can happen early January 2021.

This difficulty can be fastened as of 1.9.24. This difficulty is related just for miners, non-mining nodes are unaffected.

Geth shallow copy bug

Affected: 1.9.7 – 1.9.16

Fastened: 1.9.17

Sort: Consensus vulnerability

On 2020-07-15, John Youngseok Yang (Software program Platform Lab) reported a consensus vulnerability in Geth.

Geth’s pre-compiled dataCopy(0x00…04) contract did a shallow copy on invocation, whereas Parity’s did a deep copy. An attacker may deploy a contract that

• writes X to an EVM reminiscence area R,
• calls 0x00..04 with R as an argument,
• overwrites R to Y,
• and at last invokes the RETURNDATACOPY opcode.
• When this contract is invoked, Parity would push X on the EVM stack, whereas Geth would push Y.

Penalties

This was exploited on Ethereum Mainnet at block 11234873, transaction 0x57f7f9. Nodes have been dropped off the community, inflicting ~30 blocks to be misplaced on a sidechain. It additionally induced Infura to drop off, which induced issues for lots of people and companies who have been relying on Infura as a backend supplier.

Extra context might be present in the Geth post-mortem and Infura post-mortem and here.

DoS in .16 and .17

Affected: v1.9.16,v1.9.17

Fastened: v1.9.18

Sort: DoS vulnerability throughout block processing

A DoS vulnerability was discovered, and stuck in v1.9.18. We have now chosen to not publish the main points at this time limit.

Suggestions

Within the brief time period, we advocate that every one customers improve to geth model v1.9.24 (which ought to be constructed with Go 1.15.5) instantly. Official releases might be discovered here.

If you’re utilizing Geth through Docker, there could possibly be a couple of issues. If you’re utilizing ethereum/client-go, there are two issues to pay attention to:

1. There may be a delay earlier than the brand new picture seems on docker hub.
2. Except the Go base photos have been created rapidly sufficient, there’s an opportunity that they change into constructed with a weak model of Go.

If you’re constructing docker photos your self, (through docker construct . from the repository root), then the second difficulty may be trigger issues for you aswell.

So watch out to make sure that Go 1.15.5 is used as the bottom picture.

In the long run, we advocate that customers and miners look into various shoppers too. It’s our sturdy feeling that the resilience of the Ethereum community mustn’t depend upon any single shopper implementation.
There may be Besu, Nethermind, OpenEthereum and TurboGeth and others to select from aswell.

Please report safety vulnerabilities both through https://bounty.ethereum.org, or through bounty@ethereum.org or through security@ethereum.org.