How severe is CVE-2021-4024?

CVE-2021-4024 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-4024?

CVE-2021-4024 affects the following packages: github.com/containers/podman/v3 (Go). Ecosystems affected: Go.

How do I fix CVE-2021-4024?

Update github.com/containers/podman/v3 to 3.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-4024 is resolved across your whole dependency graph.

How do I detect CVE-2021-4024 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containers/podman/v3. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2021-4024 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2021-4024?

O3 pinpoints whether CVE-2021-4024 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2021-4024 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-4024 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-4024?

CVE-2021-4024 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 60th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2021-4024 published, and has it been updated?

CVE-2021-4024 was published on December 23, 2021 and was last updated on April 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

CVE-2021-4024

MEDIUM

Exposure of Sensitive Information to an Unauthorized Actor and Origin Validation Error in podman

Also known asGHSA-3cf2-x423-x582GO-2022-0281

Published

Dec 23, 2021

Updated

Apr 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk60th percentile+0.96%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐹github.com/containers/podman/v3

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

A flaw was found in podman. The podman machine function (used to create and manage Podman virtual machine containing a Podman process) spawns a gvproxy process on the host system. The gvproxy API is accessible on port 7777 on all IP addresses on the host. If that port is open on the host's firewall, an attacker can potentially use the gvproxy API to forward ports on the host to ports in the VM, making private services on the VM accessible to the network. This issue could be also used to interrupt the host's services by forwarding all ports to the VM.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/containers/podman/v3`	all versions	3.4.3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containers/podman/v3. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/containers/podman/v3 to 3.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-4024 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2021-4024 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2021-4024. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A flaw was found in podman. The `podman machine` function (used to create and manage Podman virtual machine containing a Podman process) spawns a `gvproxy` process on the host system. The `gvproxy` API is accessible on port 7777 on all IP addresses on the host. If that port is open on the host's firewall, an attacker can potentially use the `gvproxy` API to forward ports on the host to ports in the VM, making private services on the VM accessible to the network. This issue could be also used to interrupt the host's services by forwarding all ports to the VM.

O3 Security · Impact-Aware SCA

Is CVE-2021-4024 in your dependencies?

O3 detects CVE-2021-4024 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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