Samba
CVE-2021-20254
MEDIUM
Severity by source
AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Lifecycle Timeline
1DescriptionNVD
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.
AnalysisAI
A flaw was found in samba. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. No vendor patch available.
Technical ContextAI
This vulnerability is classified as Out-of-bounds Read (CWE-125), which allows attackers to read data from memory outside the intended buffer boundaries. 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. Affected products include: Samba, Fedoraproject Fedora, Redhat Enterprise Linux, Debian Debian Linux.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate array indices and buffer lengths. Use memory-safe languages. Enable AddressSanitizer during testing.
The RPC code generator in Samba 3.x before 3.4.16, 3.5.x before 3.5.14, and 3.6.x before 3.6.4 does not implement valida
The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x before 4.0.25, 4.1.x before 4.1
The MS-SAMR and MS-LSAD protocol implementations in Samba 3.x and 4.x before 4.2.11, 4.3.x before 4.3.8, and 4.4.x befor
Integer overflow in the read_nttrans_ea_list function in nttrans.c in smbd in Samba 3.x before 3.5.22, 3.6.x before 3.6.
NetBIOS name services daemon (nmbd) in Samba 4.0.x before 4.0.21 and 4.1.x before 4.1.11 allows remote attackers to exec
Heap-based buffer overflow in process.c in smbd in Samba 3.0, as used in the file-sharing service on the BlackBerry Play
The LDAP server in the AD domain controller in Samba 4.x before 4.1.22 does not check return values to ensure successful
Samba before 4.7.3 might allow remote attackers to obtain sensitive information by leveraging failure of the server to c
Use-after-free vulnerability in Samba 4.x before 4.7.3 allows remote attackers to execute arbitrary code via a crafted S
vfs.c in smbd in Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3, when share names with cert
A path traversal vulnerability was identified in Samba when processing client pipe names connecting to Unix domain socke
PAC parsing in MIT Kerberos 5 (aka krb5) before 1.19.4 and 1.20.x before 1.20.1 has integer overflows that may lead to r
Same weakness CWE-125 – Out-of-bounds Read
View allSame technique Buffer Overflow
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External POC / Exploit Code
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