o CVE-2021-20254: Negative idmap cache entries can cause incorrect group entries in the Samba file server process token. ======= Details ======= o CVE-2021-20254: The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. Most commonly this flaw caused the calling code to crash, but an alert user (Peter Eriksson, IT Department, Linköping University) found this flaw by noticing an unprivileged user was able to delete a file within a network share that they should have been disallowed access to. Analysis of the code paths has not allowed us to discover a way for a remote user to be able to trigger this flaw reproducibly or on demand, but this CVE has been issued out of an abundance of caution.
Bumped in https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=f10d6e6b8d366ca8b4cf89205f0e08e67b8de0bc. Tell us when ready to stable - we can replace other bug if needed.
ping
amd64 done
x86 stable
sparc done
arm done
New GLSA request filed.
arm64 done
ppc done
ppc64 done all arches done
This issue was resolved and addressed in GLSA 202105-22 at https://security.gentoo.org/glsa/202105-22 by GLSA coordinator Thomas Deutschmann (whissi).
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=a6af5ffd92963345295cf6b245e2e10d658a7965 commit a6af5ffd92963345295cf6b245e2e10d658a7965 Author: Thomas Deutschmann <whissi@gentoo.org> AuthorDate: 2021-05-26 09:48:05 +0000 Commit: Thomas Deutschmann <whissi@gentoo.org> CommitDate: 2021-05-26 09:48:15 +0000 net-fs/samba: security cleanup Bug: https://bugs.gentoo.org/786825 Package-Manager: Portage-3.0.18, Repoman-3.0.3 Signed-off-by: Thomas Deutschmann <whissi@gentoo.org> net-fs/samba/Manifest | 2 - net-fs/samba/samba-4.13.7.ebuild | 332 --------------------------------------- net-fs/samba/samba-4.13.8.ebuild | 332 --------------------------------------- 3 files changed, 666 deletions(-)
