CVE-2023-42670: Samba: ad dc busy rpc multiple listener dos
A flaw was found in Samba. It is susceptible to a vulnerability where multiple incompatible RPC listeners can be initiated, causing disruptions in the AD DC service. When Samba's RPC server experiences a high load or unresponsiveness, servers intended for non-AD DC purposes (for example, NT4-emulation "classic DCs") can erroneously start and compete for the same unix domain sockets. This issue leads to partial query responses from the AD DC, causing issues such as "The procedure number is out of range" when using tools like Active Directory Users. This flaw allows an attacker to disrupt AD DC services.
Other sources
Samba can be made to start multiple incompatible RPC listeners, disrupting service on the AD DC. When Samba's RPC server is under load, or otherwise not responding, the servers NOT built for the AD DC (eg build instead for the NT4-emulation "classic DCs") can be incorrectly started, and compete to listen on the same unix domain sockets. This then results in some queries being answered by the AD DC, and some not. "The procedure number is out of range" when starting Active Directory Users and Computers tool, however it can also be triggered maliciously, to prevent service on the AD DC.
https://bugzilla.samba.org/showbug.cgi?id=15473
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/sambato a version that resolves this vulnerability.Fixed in 4.19.1 - Upgrade
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redhat/sambato a version that resolves this vulnerability.Fixed in 4.18.8 - Upgrade
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redhat/sambato a version that resolves this vulnerability.Fixed in 4.17.12 - Upgrade
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ubuntu/sambato a version that resolves this vulnerability.Fixed in 2:4.15.13+dfsg-0ubuntu1.5 - Upgrade
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ubuntu/sambato a version that resolves this vulnerability.Fixed in 2:4.17.7+dfsg-1ubuntu2.3 - Upgrade
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ubuntu/sambato a version that resolves this vulnerability.Fixed in 2:4.18.6+dfsg-1ubuntu2.1 - Upgrade
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debian/sambato a version that resolves this vulnerability.Fixed in 2:4.17.12+dfsg-0+deb12u4Fixed in 2:4.22.11+dfsg-0+deb13u1Fixed in 2:4.22.10+dfsg-0+deb13u2Fixed in 2:4.25.1+dfsg-1 - Upgrade
Upgrade
debian/sambato a version that resolves this vulnerability.Fixed in 2:4.17.12+dfsg-0+deb12u1 - Upgrade
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debian/sambato a version that resolves this vulnerability.Fixed in 2:4.19.1+dfsg-1
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2023-42670?
CVE-2023-42670 is a vulnerability that allows for Denial of Service (DoS) attacks on Samba AD DC Busy RPC multiple listener.
Which software versions are affected by CVE-2023-42670?
The affected software versions are Samba 2:4.15.13+dfsg-0ubuntu1.5 and Samba 2:4.17.7+dfsg-1ubuntu2.3.
How can I fix CVE-2023-42670?
To fix CVE-2023-42670, update your Samba software to version 2:4.15.13+dfsg-0ubuntu1.5 or version 2:4.17.7+dfsg-1ubuntu2.3.
Where can I find more information about CVE-2023-42670?
You can find more information about CVE-2023-42670 on the CVE Mitre website (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-42670) and the Samba security page (https://www.samba.org/samba/security/CVE-2023-42670.html).
Are there any security notices related to CVE-2023-42670?
Yes, you can refer to the following security notice for more details: Ubuntu Security Notice USN-6425-1 (https://ubuntu.com/security/notices/USN-6425-1).