Bug 2391100 (CVE-2025-57849)

Summary: CVE-2025-57849 fuse: privilege escalation via excessive /etc/passwd permissions
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: gmalinko, janstey, pdelbell, rstepani, security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Deadline: 2026-03-13   

Description OSIDB Bzimport 2025-08-26 18:32:13 UTC 
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.