CVE-2021-20254 — Out-of-bounds Read in Samba

CWE-125 — Out-of-bounds Read9 documents7 sources
Severity
6.8MEDIUMNVD
OSV4.3
EPSS
1.8%
top 17.34%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
8
SambaDebian SambaDebian Linux+5 more
Timeline
PublishedMay 5
Latest updateMay 24

Description

A flaw was found in samba. 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. The highest threat from this vulnerability is to data confidentiality and …

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NExploitability: 1.6 | Impact: 5.2

Affected Packages8 packages

▶NVDsamba/samba3.6.0 — 4.12.15+2
▶debiandebian/samba< samba 2:4.13.5+dfsg-2 (bookworm)
▶Debiansamba/samba< 2:4.13.5+dfsg-2+3
▶Ubuntusamba/samba< 2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11
▶CVEListV5samba/sambasamba 4.14.1, samba 4.13.6, samba 4.12.13

Also affects: Debian Linux 9.0, Fedora 32, 33, Enterprise Linux 7.0, 8.0

🔴Vulnerability Details

3
GHSA
GHSA-3r9x-25h6-9v89: A flaw was found in samba↗2022-05-24
▶
OSV
CVE-2021-20254: A flaw was found in samba↗2021-05-05
▶
OSV
samba vulnerabilities↗2021-05-03
▶

📋Vendor Advisories

5
Microsoft
A flaw was found in samba. 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 beyon↗2021-05-11
▶
Ubuntu
Samba vulnerabilities↗2021-05-03
▶
Red Hat
samba: Negative idmap cache entries can cause incorrect group entries in the Samba file server process token↗2021-04-29
▶
Ubuntu
Samba vulnerability↗2021-04-29
▶
Debian
CVE-2021-20254: samba - A flaw was found in samba. The Samba smbd file server must map Windows group ide...↗2021
▶