SecuriTricks - CVE-2025-65849

Description

A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the Proof-of-Work nonce in constant time via mathematical deduction. NOTE: this is disputed by the Supplier because the product's objective is "to discourage automated scraping / bots, not guarantee resistance to determined attackers." The documentation states “the goal is not to provide a secure cryptographic algorithm but to use a proof-of-work mechanism that allows any capable device to decrypt the hidden data.”

Product(s) Impacted

Product	Versions
proof-of-work_obfuscation_mode	0.8.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-327

Use of a Broken or Risky Cryptographic Algorithm

The product uses a broken or risky cryptographic algorithm or protocol.

References

https://altcha.org/docs/v2/obfuscation/

https://github.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194

https://github.com/eternal-flame-AD/altcha-deobfs

CVSS Score

9.1 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: LOW
Privileges Required: NONE
Scope: UNCHANGED
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: NONE

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

View Vector String

Timeline

Published: Dec. 8, 2025, 7:15 p.m.
Last Modified: Dec. 11, 2025, 3:15 p.m.

Status : Awaiting Analysis

CVE has been marked for Analysis. Normally once in this state the CVE will be analyzed by NVD staff within 24 hours.

More info

Source

cve@mitre.org

CVE-2025-65849