Summary
A vulnerability in the Eclipse Vert.x toolkit results in a memory leak due to using Netty FastThreadLocal data structures. Specifically, when the Vert.x HTTP client establishes connections to different hosts, triggering the memory leak. The leak can be accelerated with intimate runtime knowledge, allowing an attacker to exploit this vulnerability. For instance, a server accepting arbitrary internet addresses could serve as an attack vector by connecting to these addresses, thereby accelerating the memory leak.
Impact
CVE-2024-1023 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low 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. A fixed version is available (4.5.2, 4.4.7); upgrading removes the vulnerable code path.
Affected versions
Security releases
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.
Remediation advice
io.vertx:vertx-core to 4.5.2 or later; io.vertx:vertx-core to 4.4.7 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2024-1023? CVE-2024-1023 is a medium-severity security vulnerability in io.vertx:vertx-core (maven), affecting versions >= 4.5.0, < 4.5.2. It is fixed in 4.5.2, 4.4.7.
- How severe is CVE-2024-1023? CVE-2024-1023 has a CVSS score of 6.5 (Medium). 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 io.vertx:vertx-core are affected by CVE-2024-1023? io.vertx:vertx-core (maven) versions >= 4.5.0, < 4.5.2 is affected.
- Is there a fix for CVE-2024-1023? Yes. CVE-2024-1023 is fixed in 4.5.2, 4.4.7. Upgrade to this version or later.
- Is CVE-2024-1023 exploitable, and should I be worried? Whether CVE-2024-1023 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-2024-1023 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-2024-1023?
- Upgrade
io.vertx:vertx-coreto 4.5.2 or later - Upgrade
io.vertx:vertx-coreto 4.4.7 or later
- Upgrade