Summary
Jenkins 2.218 and earlier, LTS 2.204.1 and earlier does not serve the X-Frame-Options: deny HTTP header on REST API responses to protect against clickjacking attacks. An attacker could exploit this by routing the victim through a specially crafted web page that embeds a REST API endpoint in an iframe and tricking the user into performing an action which would allow for the attacker to learn the content of that REST API endpoint.
Jenkins 2.219, LTS 2.204.2 now adds the X-Frame-Options: deny HTTP header to REST API responses, which prevents these types of clickjacking attacks.
Impact
CVE-2020-2105 has a CVSS score of 3.1 (Low). The vector is network-reachable, no privileges required, and user interaction required. 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 (2.204.2, 2.219); 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
org.jenkins-ci.main:jenkins-core to 2.204.2 or later; org.jenkins-ci.main:jenkins-core to 2.219 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2020-2105? CVE-2020-2105 is a low-severity security vulnerability in org.jenkins-ci.main:jenkins-core (maven), affecting versions <= 2.204.1. It is fixed in 2.204.2, 2.219.
- How severe is CVE-2020-2105? CVE-2020-2105 has a CVSS score of 3.1 (Low). 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 org.jenkins-ci.main:jenkins-core are affected by CVE-2020-2105? org.jenkins-ci.main:jenkins-core (maven) versions <= 2.204.1 is affected.
- Is there a fix for CVE-2020-2105? Yes. CVE-2020-2105 is fixed in 2.204.2, 2.219. Upgrade to this version or later.
- Is CVE-2020-2105 exploitable, and should I be worried? Whether CVE-2020-2105 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-2020-2105 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-2020-2105?
- Upgrade
org.jenkins-ci.main:jenkins-coreto 2.204.2 or later - Upgrade
org.jenkins-ci.main:jenkins-coreto 2.219 or later
- Upgrade