| Name | 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-3792-1, DSA-5525-1, DSA-5647-1, ELA-1203-1, ELA-1212-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| samba (PTS) | jessie, jessie (lts) | 2:4.2.14+dfsg-0+deb8u16 | fixed |
| stretch (security) | 2:4.5.16+dfsg-1+deb9u4 | vulnerable | |
| stretch (lts), stretch | 2:4.5.16+dfsg-1+deb9u5 | fixed | |
| buster (security), buster, buster (lts) | 2:4.9.5+dfsg-5+deb10u5 | fixed | |
| bullseye (security), bullseye | 2:4.13.13+dfsg-1~deb11u6 | fixed | |
| bookworm (security), bookworm | 2:4.17.12+dfsg-0+deb12u1 | fixed | |
| sid, trixie | 2:4.21.1+dfsg-2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| samba | source | jessie | 2:4.2.14+dfsg-0+deb8u16 | ELA-1212-1 | ||
| samba | source | stretch | 2:4.5.16+dfsg-1+deb9u5 | ELA-1203-1 | ||
| samba | source | buster | 2:4.9.5+dfsg-5+deb10u5 | DLA-3792-1 | ||
| samba | source | bullseye | 2:4.13.13+dfsg-1~deb11u6 | DSA-5647-1 | ||
| samba | source | bookworm | 2:4.17.12+dfsg-0+deb12u1 | DSA-5525-1 | ||
| samba | source | (unstable) | 2:4.19.1+dfsg-1 |
https://www.samba.org/samba/security/CVE-2023-4091.html
In scope for continued Samba support
Fixed by: https://git.samba.org/?p=samba.git;a=commit;h=b08a60160e6ab8d982d31844bcbf7ab67ff3a8de (samba-4.17.12)
Fixed by: https://git.samba.org/?p=samba.git;a=commit;h=8b26f634372f11edcbea33dfd68a3d57889dfcc5 (samba-4.17.12)