CVE-2021-4024: A flaw was found in podman. The `podman machine` function (used to create and manage Podman virtual machine containing a Podman process) spawns a `gvp...

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

EPSS Probability

1.06%

60.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Podman Project	Podman	>= 3.3.0, < 3.4.3
Fedoraproject	Fedora	34
Fedoraproject	Fedora	35
Redhat	Enterprise Linux	8.0

References

Timeline

Published: Dec 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-4024?

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.

How severe is CVE-2021-4024?

CVE-2021-4024 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.06% probability of exploitation in the next 30 days.

How do I fix CVE-2021-4024?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.