Bug 2241885 (CVE-2023-42670) - CVE-2023-42670 samba: AD DC Busy RPC multiple listener DoS
Summary: CVE-2023-42670 samba: AD DC Busy RPC multiple listener DoS
Status: NEW
Alias: CVE-2023-42670
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Product Security
QA Contact:
Depends On: 2243232
Blocks: 2228383
TreeView+ depends on / blocked
Reported: 2023-10-03 07:34 UTC by TEJ RATHI
Modified: 2023-11-03 07:41 UTC (History)
5 users (show)

Fixed In Version: samba 4.19.1, samba 4.18.8, samba 4.17.12
Doc Type: If docs needed, set a value
Doc Text:
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.
Clone Of:
Last Closed:

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Description TEJ RATHI 2023-10-03 07:34:40 UTC
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.


Comment 1 TEJ RATHI 2023-10-11 10:44:45 UTC
This CVE is now Public:

Comment 2 TEJ RATHI 2023-10-11 10:46:15 UTC
Created samba tracking bugs for this issue:

Affects: fedora-all [bug 2243232]

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