CVE-2023-4091
Description
A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS module "acl_xattr" is configured with "acl_xattr:ignore system acls = yes". The SMB protocol allows opening files when the client requests read-only access but then implicitly truncates the opened file to 0 bytes if the client specifies a separate OVERWRITE create disposition request. The issue arises in configurations that bypass kernel file system permissions checks, relying solely on Samba's permissions.
How to fix
- samba samba4.17.12, 4.18.8, 4.19.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| samba samba | v < 4.17.12, 4.18.0 ≤ v < 4.18.8, 4.19.0 ≤ v < 4.19.1 | 4.17.12, 4.18.8, 4.19.1 |
| fedoraproject fedora | 39 | — |
| redhat storage | 3.0 | — |
| redhat enterprise_linux | 8.0 | — |
| redhat enterprise_linux_eus | 9.0 | — |
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