Vulnerabilities in pkg:maven/com.github.penggle/kaptcha

PACKAGE
Advisory Identifier: GHSA-8q89-pwhh-7wfq
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Advisory Summary

CVE-2018-18531 is a CRITICAL (CVSS 9.8) kaptcha vulnerability (CWE-330: Use of Insufficiently Random Values) affecting Kaptcha libraries in the Maven ecosystem. The issue involves kaptcha. Remediation is available in the latest vendor maintenance releases.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:maven/com.github.penggle/kaptcha

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:maven/com.github.penggle/kaptcha. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-8q89-pwhh-7wfq CVE-2018-18531 CRITICAL Use of Insufficiently Random Values in penggle:kaptcha

CVE-2018-18531 at a Glance

CVE Identifier CVE-2018-18531
GHSA Identifier GHSA-8q89-pwhh-7wfq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-330: Use of Insufficiently Random Values
Affected Product Kaptcha
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2018-18531

To remediate this vulnerability, upgrade all affected Kaptcha dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

com.github.penggle:kaptcha fixed: Latest secure release 
<dependency>
    <groupId>com.github.penggle</groupId>
    <artifactId>kaptcha</artifactId>
    <version>Latest secure release</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=com.github.penggle

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2018-18531, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.github.penggle

Analyze the terminal output to locate any version of Kaptcha in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.github.penggle command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-330: Use of Insufficiently Random Values, where the product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. In Kaptcha, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2018-18531 Affected Kaptcha Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
com.github.penggle:kaptcha
maven/com.github.penggle/kaptcha
Maven
≤ 2.3.2

References

NVD — CVE-2018-18531 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-18531
Kaptcha Source Repository REPOSITORY
https://github.com/penggle/kaptcha/issues/3
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-8q89-pwhh-7wfq
Kaptcha Source Repository REPOSITORY
https://github.com/penggle/kaptcha

Frequently Asked Questions

What is CVE-2018-18531?
CVE-2018-18531 is a security vulnerability in Kaptcha involving kaptcha under CWE-330: Use of Insufficiently Random Values.
Which Kaptcha versions are affected?
Affected versions include releases prior to current release patches across affected packages: com.github.penggle:kaptcha.
What version fixes CVE-2018-18531?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is kaptcha affected?
Yes, com.github.penggle:kaptcha is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2018-18531?
CVE-2018-18531 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2018-18531?
CVE-2018-18531 is classified under CWE-330: Use of Insufficiently Random Values (The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.).
How can I check Maven dependencies for CVE-2018-18531?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.github.penggle'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8q89-pwhh-7wfq",
  "modified" : "2022-09-14T21:57:07Z",
  "published" : "2018-10-23T16:08:56Z",
  "aliases" : [ "CVE-2018-18531" ],
  "summary" : "Use of Insufficiently Random Values in penggle:kaptcha",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.github.penggle:kaptcha"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.3.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-18531"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/penggle/kaptcha/issues/3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-8q89-pwhh-7wfq"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/penggle/kaptcha"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-330" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:26:18Z",
    "nvd_published_at" : null
  }
}