Summary
Denial of Service in Go-Ethereum
Go-Ethereum 1.10.9 nodes crash (denial of service) after receiving a serial of messages and cannot be recovered. They will crash with "runtime error: invalid memory address or nil pointer dereference" and arise a SEGV signal.
Impact
The application dereferences a null pointer, causing a crash. Typical impact: denial of service via crash.
CVE-2021-43668 has a CVSS score of 5.5 (Medium). The vector is requires local access, 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. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
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.
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In the interim: Keep the dependency up to date. Ensure all pointers and return values are checked for null before use.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2021-43668? CVE-2021-43668 is a medium-severity null pointer dereference vulnerability in github.com/ethereum/go-ethereum (go), affecting versions <= 1.10.9. No fixed version is listed yet. The application dereferences a null pointer, causing a crash.
- How severe is CVE-2021-43668? CVE-2021-43668 has a CVSS score of 5.5 (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 github.com/ethereum/go-ethereum are affected by CVE-2021-43668? github.com/ethereum/go-ethereum (go) versions <= 1.10.9 is affected.
- Is there a fix for CVE-2021-43668? No fixed version is listed for CVE-2021-43668 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2021-43668 exploitable, and should I be worried? Whether CVE-2021-43668 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-2021-43668 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-2021-43668? No fixed version is listed yet. In the interim: Keep the dependency up to date. Ensure all pointers and return values are checked for null before use.