Vulnerability 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 integrity.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Samba | Samba | >= 3.6.0, < 4.12.15 |
| Fedoraproject | Fedora | 32 |
| Redhat | Enterprise Linux | 7.0 |
| Debian | Debian Linux | 9.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1949442Issue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00023.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202105-22Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210430-0001/Third Party Advisory
- https://www.samba.org/samba/security/CVE-2021-20254.htmlVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1949442Issue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00023.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202105-22Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210430-0001/Third Party Advisory
- https://www.samba.org/samba/security/CVE-2021-20254.htmlVendor Advisory
FAQ
What is CVE-2021-20254?
CVE-2021-20254 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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...
How severe is CVE-2021-20254?
CVE-2021-20254 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-20254?
Check the references section above for vendor advisories and patch information. Affected products include: Samba Samba, Fedoraproject Fedora, Redhat Enterprise Linux, Debian Debian Linux.