by Kastro
Paper/Archive/CVE-2025-65849

CVE-2025-65849

mitre — 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…

EPSS 0.2%CVSS 9.1
critical.is priorityof 100
30
CVSS 9.1 (ADP)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 12.6.126 × 202.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.”

Affected

ProductAffectedFixed inSource
n/an/a–CNA

Scores by source

CISA ADP9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194refaltcha.org/docs/v2/obfuscationrefgithub.com/eternal-flame-AD/altcha-deobfs