Vulnerability in Kaptcha Project

CVE-2018-18531

text/impl/DefaultTextCreator.java, text/impl/ChineseTextProducer.java, and text/impl/FiveLetterFirstNameTextCreator.java in kaptcha 2.3.2 use the Random (rather than SecureRandom) function for generating CAPTCHA values, which makes it easier for remote attackers to bypass intended access restrictions via a brute-force approach.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.015 (72.8th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2018-18531: held from 0.015 to 0.015.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-18531?
CVE-2018-18531 is a critical-severity vulnerability in Kaptcha Project, classified under Use of Insufficiently Random Values. CVSS score: 9.8/10. Published 2018-10-19.
How severe is CVE-2018-18531?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2018-18531 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.