CVE-2025-57849: Fuse: privilege escalation via excessive /etc/passwd permissions
A container privilege escalation flaw was found in certain Fuse images. This issue stems from the /etc/passwd file being created with group-writable permissions during build time. In certain conditions, an attacker who can execute commands within an affected container, even as a non-root user, can leverage their membership in the root group to modify the /etc/passwd file. This could allow the attacker to add a new user with any arbitrary UID, including UID 0, leading to full root privileges within the container.
Other sources
The /etc/passwd file is created during build time with group-writable permissions. In certain conditions, an attacker who can execute commands within an affected container, even as a non-root user, may be able to leverage their membership in the root group to modify the /etc/passwd file. This could allow the attacker to add a new user with any arbitrary UID, including UID 0, leading to full root privileges within the container.
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-57849?
The severity of CVE-2025-57849 is rated as medium with a CVSS score of 6.4.
How do I fix CVE-2025-57849?
To fix CVE-2025-57849, ensure that the /etc/passwd file in the Fuse image is created with the correct permissions to prevent group-writable access.
What does CVE-2025-57849 exploit?
CVE-2025-57849 exploits excessive group-writable permissions on the /etc/passwd file, allowing privilege escalation.
Who is affected by CVE-2025-57849?
CVE-2025-57849 affects users of certain Fuse images that have the vulnerable /etc/passwd permissions during build time.
What are the potential impacts of CVE-2025-57849?
The potential impacts of CVE-2025-57849 include unauthorized privilege escalation by non-root users within the affected container.