CVE-2020-5303
Tendermint before versions 0.33.3, 0.32.10, and 0.31.12 has a denial-of-service vulnerability.
Does this matter?
Lower severity and a low EPSS score (1.37%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 3.7 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- EPSS
- 1.37% probability · 72th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-789, CWE-787
- Affected
- tendermint/tendermint
- Source
- security-advisories@github.com
EPSS 1.4% since 26 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/tendermint/tendermint/commit/e2d6859afd7dba4cf97c7f7d412e7d8fc908d1cdPatch, Third Party Advisory
- https://github.com/tendermint/tendermint/security/advisories/GHSA-v24h-pjjv-mcp6Third Party Advisory
- https://hackerone.com/reports/820317Permissions Required, Third Party Advisory
- https://github.com/tendermint/tendermint/commit/e2d6859afd7dba4cf97c7f7d412e7d8fc908d1cdPatch, Third Party Advisory
- https://github.com/tendermint/tendermint/security/advisories/GHSA-v24h-pjjv-mcp6Third Party Advisory
- https://hackerone.com/reports/820317Permissions Required, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.