CVE-2021-21271
6.5 · MEDIUMOverview
CVE-2021-21271 is a medium-severity vulnerability affecting tendermint tendermint. It was published on January 26, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Tendermint Core is an open source Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine - written in any programming language - and securely replicates it on many machines. Tendermint Core v0.34.0 introduced a new way of handling evidence of misbehavior. As part of this, we added a new Timestamp field to Evidence structs. This timestamp would be calculated using the same algorithm that is used when a block is created and proposed. (This algorithm relies on the timestamp of the last commit from this specific block.) In Tendermint Core v0.34.0-v0.34.2, the consensus reactor is responsible for forming DuplicateVoteEvidence whenever double signs are observed. However, the current block is still “in flight” when it is being formed by the consensus reactor. It hasn’t been finalized through network consensus yet. This means that different nodes in the network may observe different “last commits” when assigning a timestamp to DuplicateVoteEvidence. In turn, different
Remediation
Check the references section for vendor advisories and patches from tendermint. Update tendermint to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| tendermint | tendermint | 0.34.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-21271?
CVE-2021-21271 is a medium-severity vulnerability affecting tendermint tendermint. It was published on January 26, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2021-21271?
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-21271?
Check the references section for vendor advisories and patches from tendermint. Update tendermint to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-21271?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-21271 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
Related MEDIUM CVEs from 2021
View all →Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is
Integer Overflow in memory allocating functions. Zephyr versions >= 1.14.2, >= 2.4.0 contain Integer
Magento versions 2.4.2 (and earlier), 2.4.1-p1 (and earlier) and 2.3.6-p1 (and earlier) are affected
Certain NETGEAR devices are affected by out-of-bounds reads and writes. This affects R6400 before 1.
NETGEAR R6400 devices before 1.0.1.70 are affected by a stack-based buffer overflow by an authentica
Next.js is an open source website development framework to be used with the React library. In affect
Authenticated Stored Cross-Site Scripting (XSS) vulnerability in YITH Maintenance Mode (WordPress pl
Multiple Authenticated Stored Cross-Site Scripting (XSS) vulnerabilities in YITH Maintenance Mode (W
An attacker with physical access to Boston Scientific Zoom Latitude Model 3120 can remove the hard d
Grafana is an open-source platform for monitoring and observability. In affected versions if an atta
A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QmailAgen