Vulnerability in Samba: CVE-2021-23192
Summary
CVE-2021-23192: A flaw was found in the way samba implemented DCE/RPC. Affects samba across 2 version ranges.
< 4.13.17-r0
>= 25f2fe02a615e2cf906b6fa495acd8ea0aa9998a, < db11778b57610e24324aa4342f89918f66157d71
Fixed in 4.13.17-r0. How to fix ↓
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Background
Samba is an open-source software suite that provides seamless file and print services to SMB/CIFS clients. It allows interoperability between Linux/Unix servers and Windows-based clients. However, a vulnerability has been discovered in Samba that could potentially allow an attacker to bypass signature requirements by replacing fragments of a large DCE/RPC request.
Vulnerability Detail
The flaw in Samba's implementation of DCE/RPC arises when a client sends an excessively large DCE/RPC request and chooses to fragment it. In such a scenario, an attacker can replace subsequent fragments with their own data, effectively bypassing the signature requirements. This could lead to unauthorized access, data manipulation, or other malicious activities on the affected Samba server.
How To Fix
Minimum fixed version
4.13.17-r0
This is the first release that contains the fix.
sudo apk add --upgrade sambaTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, it is advisable to disable DCE/RPC functionality on the affected Samba server until the package can be updated. This can be achieved by modifying the Samba configuration file and commenting out or removing the relevant DCE/RPC-related configurations. However, this workaround may impact certain functionalities that rely on DCE/RPC.
Conclusion
In conclusion, the vulnerability in Samba's DCE/RPC implementation allows an attacker to bypass signature requirements, potentially leading to unauthorized access or data manipulation. It is crucial to update the Samba package to the fixed versions mentioned or apply the temporary workaround of disabling DCE/RPC functionality. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
Samba is an open-source software suite that enables file and print services interoperability between Linux/Unix servers and Windows-based clients.
DCE/RPC (Distributed Computing Environment/Remote Procedure Call) is a protocol used by Samba for remote procedure calls between networked systems.
This vulnerability allows an attacker to bypass signature requirements by replacing fragments of a large DCE/RPC request, potentially leading to unauthorized access or data manipulation on the affected Samba server.
To fix this vulnerability, it is advised to update the Samba package to the fixed versions mentioned in the 'how_to_fix' section.
Yes, a temporary workaround is to disable DCE/RPC functionality on the affected Samba server until the package can be updated. However, this may impact certain functionalities relying on DCE/RPC.
Related vulnerabilities
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