CVE-2024-6863: h2o — Exploit

Description

In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their choosing. The chosen key can also be overwritten, resulting in ransomware-like behavior. This vulnerability makes it possible for an attacker to encrypt arbitrary files with keys of their choice, making it exceedingly difficult for the target to recover the keys needed for decryption.

Is your site exposed to CVE-2024-6863?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Weakness Type (CWE)

CWE-749 CWE-749

Affected Products

Vendor	Product	Versions
h2o	h2o	All

References

Exploits

https://huntr.com/bounties/10f55937-0cba-4530-897f-2abf30ed5270

Frequently Asked Questions

What is CVE-2024-6863? +

In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their choosing. The chosen key can also be overwritten, resulting in ransomware-like behavior. This vulnerability makes it possible for an attacker to encrypt arbitrary files with keys of their choice, making it exceedingly difficult for the target to recover the keys needed for decryption. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2024-6863? +

CVE-2024-6863 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-6863? +

CVE-2024-6863 affects products from h2o, specifically: h2o. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-6863? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-47899

The Electron preload script in Logseq exposes an API method that allows the renderer process to invoke IPC handlers without …

CVE-2025-34114

A client-side security misconfiguration vulnerability exists in OpenBlow whistleblowing platform across multiple versions and default deployments, due to the absence …

CVE-2022-31491 10.0

Voltronic Power ViewPower through 1.04-24215, ViewPower Pro through 2.0-22165, and PowerShield Netguard before 1.04-23292 allows a remote attacker to run …

CVE-2026-55454 9.9

Appsmith is a platform to build admin panels, internal tools, and dashboards. Prior to 2.1, the bundled Caddy reverse-proxy's admin …

CVE-2024-32764 9.9

A missing authentication for critical function vulnerability has been reported to affect myQNAPcloud Link. If exploited, the vulnerability could allow …

CVE-2024-25675 9.8

An issue was discovered in MISP before 2.4.184. A client does not need to use POST to start an export …

CVE-2024-6863