What’s Vulnerable › Vulnerabilities

CVE-2021-4300: ghostlander Halcyon Block Verification main.cpp AddToBlockIndex access control

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-01-04 · updated 2026-06-17
• Weakness: CWE-284

Description

A vulnerability has been found in ghostlander Halcyon and classified as critical. Affected by this vulnerability is the function CBlock::AddToBlockIndex of the file src/main.cpp of the component Block Verification. The manipulation leads to improper access controls. The attack can be launched remotely. Upgrading to version 1.1.1.0-hal is able to address this issue. The identifier of the patch is 0675b25ae9cc10b5fdc8ea3a32c642979762d45e. It is recommended to upgrade the affected component. The identifier VDB-217417 was assigned to this vulnerability.

Affected products

• ghostlander Halcyon: before 1.1.1.0 — fixed in 1.1.1.0

How to fix

Upgrade to a fixed version: ghostlander Halcyon 1.1.1.0. Check the vendor advisory for mitigations.

References

• https://github.com/ghostlander/Halcyon/commit/0675b25ae9cc10b5fdc8ea3a32c642979762d45e
• https://github.com/ghostlander/Halcyon/releases/tag/v1.1.1.0-hal
• https://vuldb.com/?ctiid.217417
• https://vuldb.com/?id.217417
• https://github.com/ghostlander/Halcyon/commit/0675b25ae9cc10b5fdc8ea3a32c642979762d45e
• https://github.com/ghostlander/Halcyon/releases/tag/v1.1.1.0-hal
• https://vuldb.com/?ctiid.217417
• https://vuldb.com/?id.217417

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