Summary
Apache Commons BCEL vulnerable to out-of-bounds write
Apache Commons BCEL has a number of APIs that would normally only allow changing specific class characteristics. However, due to an out-of-bounds writing issue, these APIs can be used to produce arbitrary bytecode. This could be abused in applications that pass attacker-controllable data to those APIs, giving the attacker more control over the resulting bytecode than otherwise expected. Update to Apache Commons BCEL 6.6.0.
Impact
A write operation targets a memory location beyond the intended buffer boundary. Typical impact: memory corruption, crash, or arbitrary code execution.
CVE-2022-42920 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. A fixed version is available (6.6.0); 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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2022-42920? CVE-2022-42920 is a critical-severity out-of-bounds write vulnerability in org.apache.bcel:bcel (maven), affecting versions < 6.6.0. It is fixed in 6.6.0. A write operation targets a memory location beyond the intended buffer boundary.
- How severe is CVE-2022-42920? CVE-2022-42920 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 org.apache.bcel:bcel are affected by CVE-2022-42920? org.apache.bcel:bcel (maven) versions < 6.6.0 is affected.
- Is there a fix for CVE-2022-42920? Yes. CVE-2022-42920 is fixed in 6.6.0. Upgrade to this version or later.
- Is CVE-2022-42920 exploitable, and should I be worried? Whether CVE-2022-42920 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-2022-42920 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-2022-42920? Upgrade
org.apache.bcel:bcelto 6.6.0 or later.