CVE-2020-5303 Information

Description

Tendermint before versions 0.33.3 0.32.10 and 0.31.12 has a denial-of-service vulnerability. Tendermint does not limit the number of P2P connection requests. For each p2p connection it allocates XXX bytes. Even though this memory is garbage collected once the connection is terminated (due to duplicate IP or reaching a maximum number of inbound peers) temporary memory spikes can lead to OOM (Out-Of-Memory) exceptions. Additionally Tendermint does not reclaim activeID of a peer after it’s removed in Mempool reactor. This does not happen all the time. It only happens when a connection fails (for any reason) before the Peer is created and added to all reactors. RemovePeer is therefore called before AddPeer which leads to always growing memory (activeIDs map). The activeIDs map has a maximum size of 65535 and the node will panic if this map reaches the maximum. An attacker can create a lot of connection attempts (exploiting above denial of service) which ultimately will lead to the node panicking. These issues are patched in Tendermint 0.33.3 and 0.32.10.

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Reference

https://github.com/tendermint/tendermint/commit/e2d6859afd7dba4cf97c7f7d412e7d8fc908d1cd https://github.com/tendermint/tendermint/security/advisories/GHSA-v24h-pjjv-mcp6 https://hackerone.com/reports/820317

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

LOW

Base Severity

3.7