A malformed image that defines an environment variable with only a key (and no value) can cause the Podman runtime to copy that variable from the host into the container. If the variable name is an asterisk (*), Podman will copy every host environment variable into the container’s environment. This allows a malicious image to exfiltrate all environment variables that are set in the session where the container is launched, potentially exposing secrets such as API tokens, passwords, or other sensitive data. The weakness is a combination of CWE-200 (Information Exposure) and CWE-668 (Improper Access Control).

The vulnerability affects the Podman container tool family from release 1.8.1 through 5.8.4. Versions 5.8.4 and 6.0.0 contain the fix. The affected product is Podman, as distributed by the Podman Container Tools organization.

The CVSS score of 7.5 reflects a high impact to confidentiality when the flaw is exploited. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is a local attacker who controls the image registry or otherwise can supply images to the host; by crafting an image with a key-only or * environment variable, the attacker can cause Podman to leak host environment data into the container. The exploit requires no additional privileges beyond the ability to run podman with the malicious image.