CVE-2018-18531 json
Use of Insufficiently Random Values in penggle:kaptcha
published 8y ago modified 4mo ago also GHSA-8q89-pwhh-7wfq , EUVD-2018-0553
- cvss
- 9.8
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.5%
- EPSS 1.5% chance of exploitation in 30 days, percentile 73%
- public exploits
- 0
- none known
Summary
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.
Is CVE-2018-18531 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
1.47% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 9.8 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:P/I:N/A:N |
| GitHub | 3.0 | 9.8 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | com.github.penggle:kaptcha | <=2.3.2 |
no fix listed |
Classification
- Weakness
-
- CWE-330 Use of Insufficiently Random Values
References
-
github.com
/penggle/kaptcha/issues/3
web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2018-18531
advisory
-
github.com
/advisories/GHSA-8q89-pwhh-7wfq
advisory
-
github.com
/penggle/kaptcha
package
Sources
- CVE List CVE-2018-18531
- GitHub Advisory GHSA-8q89-pwhh-7wfq
- NVD CVE-2018-18531
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.