What is CVE-2018-18531?

CVE-2018-18531 is a critical-severity use of insufficiently random values vulnerability in com.github.penggle:kaptcha (maven), affecting versions <= 2.3.2. No fixed version is listed yet. Security-sensitive operations rely on values that are predictable or insufficiently random.

How severe is CVE-2018-18531?

CVE-2018-18531 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of com.github.penggle:kaptcha are affected by CVE-2018-18531?

com.github.penggle:kaptcha (maven) versions <= 2.3.2 is affected.

Is there a fix for CVE-2018-18531?

No fixed version is listed for CVE-2018-18531 yet. Monitor the advisory for updates and apply mitigations in the interim.

Is CVE-2018-18531 exploitable, and should I be worried?

Whether CVE-2018-18531 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2018-18531 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2018-18531 in com.github.penggle:kaptcha

Q: How severe is CVE-2018-18531?

CVE-2018-18531 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of com.github.penggle:kaptcha are affected by CVE-2018-18531?

com.github.penggle:kaptcha (maven) versions <= 2.3.2 is affected.

Q: Is there a fix for CVE-2018-18531?

No fixed version is listed for CVE-2018-18531 yet. Monitor the advisory for updates and apply mitigations in the interim.

Q: Is CVE-2018-18531 exploitable, and should I be worried?

Whether CVE-2018-18531 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2018-18531 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2018-18531?

No fixed version is listed yet. In the interim: Use a cryptographically secure random number generator (CSPRNG) for all security-sensitive values.

Summary

Use of Insufficiently Random Values in penggle:kaptcha

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.

Impact

Security-sensitive operations rely on values that are predictable or insufficiently random. Typical impact: forged tokens, guessable identifiers, or broken cryptographic protocols.

CVE-2018-18531 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Affected versions

com.github.penggle:kaptcha (<= 2.3.2)

Security releases

Not available

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

No fixed version is listed for CVE-2018-18531 yet.

In the interim: Use a cryptographically secure random number generator (CSPRNG) for all security-sensitive values.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2018-18531? CVE-2018-18531 is a critical-severity use of insufficiently random values vulnerability in com.github.penggle:kaptcha (maven), affecting versions <= 2.3.2. No fixed version is listed yet. Security-sensitive operations rely on values that are predictable or insufficiently random.
How severe is CVE-2018-18531? CVE-2018-18531 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of com.github.penggle:kaptcha are affected by CVE-2018-18531? com.github.penggle:kaptcha (maven) versions <= 2.3.2 is affected.
Is there a fix for CVE-2018-18531? No fixed version is listed for CVE-2018-18531 yet. Monitor the advisory for updates and apply mitigations in the interim.
Is CVE-2018-18531 exploitable, and should I be worried? Whether CVE-2018-18531 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2018-18531 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2018-18531? No fixed version is listed yet. In the interim: Use a cryptographically secure random number generator (CSPRNG) for all security-sensitive values.