CVE-2021-20199 is a medium-severity (CVSS 5.9) CWE-346 vulnerability in github.com/containers/podman/v3. 1 public exploit reference exists, so weaponization risk is real. A fix is available for github.com/containers/podman/v3 — see the affected versions and patch details below.
Podman Origin Validation Error
EPSS Exploitation Probability
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.
How urgent is this, really
CVE-2021-20199 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/containers/podman/v3Real-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
Rootless containers run with Podman, receive all traffic with a source IP address of 127.0.0.1 (including from remote hosts). This impacts containerized applications that trust localhost (127.0.01) connections by default and do not require authentication. This issue affects Podman 1.8.0 onwards.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/containers/podman/v3 | all versions | 3.0.0go get github.com/containers/podman/v3@v3.0.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containers/podman/v3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/containers/podman/v3 to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-20199 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-20199 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-20199. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This issue does not affect Podman prior to version 1.8.0. Podman shipped in the following products are therefore not affected: * Red Hat Enterprise Linux 7 Extras * Red Hat Enterprise Linux 8 Container Tools stream 1.0 * Red Hat Enterprise Linux 8 Container Tools stream 2.0 * OpenShift Container Platform 3.11 *…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 8 | container-tools:rhel8-8040020210407081426.59631bd5 | RHSA-2021:1796 |
| Red Hat Enterprise Linux 9 | podman-2:4.2.0-3.el9 | RHSA-2022:7954 |
Frequently Asked Questions
Is CVE-2021-20199 in your dependencies?
O3 Security finds CVE-2021-20199 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.