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.

Published: 2021-12-23 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-4024 is rated Low Risk (35.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.10%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-4024

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.15% 0.10% -0.06%
2 2025-11-18 0.09% 0.15% +0.06%
3 2025-03-17 — 0.09% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-4024

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 2.5 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2021-4024

GitHub Security Advisory for CVE-2021-4024

GHSA-3cf2-x423-x582 · Severity: medium · Ecosystem: go — Exposure of Sensitive Information to an Unauthorized Actor and Origin Validation Error in podman

OS Trackers for CVE-2021-4024

vendor priority summary link
alpine medium CVE-2021-4024: 1 source package rows (podman); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2021-4024
debian unimportant CVE-2021-4024 unimportant priority: Debian including 1 source packages (libpod), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. https://security-tracker.debian.org/tracker/CVE-2021-4024
gentoo high CVE-2021-4024: 1 GLSA(s) (202407-12), 1 atom(s) (app-containers/podman); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-4024
redhat medium — https://access.redhat.com/security/cve/CVE-2021-4024
suse medium CVE-2021-4024 severity moderate: SUSE including 94 source package names (1.8.6.0.3.2.5:libseccomp2-2.5.3-150300.10.5.1, 14.1-rev1.0.0-build2.2.43:libseccomp2-2.5.3-150300.10.5.1, …), 188 product×package rows across 77 product lines (Container bci/bci-init, Container rancher/elemental-teal-rt/5.4, … (77 product lines)): Fixed 180, Known Not Affected 8. https://www.suse.com/security/cve/CVE-2021-4024/
ubuntu medium CVE-2021-4024 medium priority: Ubuntu including 1 source packages (libpod), 13 status rows across 13 suites (hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 3, DNE 2. https://ubuntu.com/security/CVE-2021-4024

Affected software / configurations for CVE-2021-4024

Vendor Product Version Raw CPE
podman_project podman >= 3.3.0, < 3.4.3 cpe:2.3:a:podman_project:podman:*:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*

References for CVE-2021-4024

cvelogic Threat Intelligence