Out-of-bounds Read in Samba
CVE-2021-20254
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 integrity.
Vulnerability class: Buffer Overflow
EPSS: 0.016 (73.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Samba
- Debian Debian_linux — versions 9.0
- Fedoraproject Fedora — versions 32, 33
- Redhat Enterprise_linux — versions 7.0, 8.0
- N/a Samba — versions samba 4.14.1, samba 4.13.6, samba 4.12.13
Weakness classification (CWE)
References
- secalert@redhat.com (Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (x_refsource_MISC, Vendor Advisory)
- secalert@redhat.com (Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (x_refsource_FEDORA, vendor-advisory)
- secalert@redhat.com (x_refsource_FEDORA, vendor-advisory)
- secalert@redhat.com (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- secalert@redhat.com (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-20254?
- CVE-2021-20254 is a medium-severity vulnerability in Samba, classified under Out-of-bounds Read. CVSS score: 6.8/10. Published 2021-05-05.
- How severe is CVE-2021-20254?
- Medium severity. CVSS v3 base score is 6.8 out of 10.