CVE-2023-42669: Samba: "rpcecho" development server allows denial of service via sleep() call on ad dc
A vulnerability was found in Samba's "rpcecho" development server, a non-Windows RPC server used to test Samba's DCE/RPC stack elements. This vulnerability stems from an RPC function that can be blocked indefinitely. The issue arises because the "rpcecho" service operates with only one worker in the main RPC task, allowing calls to the "rpcecho" server to be blocked for a specified time, causing service disruptions. This disruption is triggered by a "sleep()" call in the "dcesrvechoTestSleep()" function under specific conditions. Authenticated users or attackers can exploit this vulnerability to make calls to the "rpcecho" server, requesting it to block for a specified duration, effectively disrupting most services and leading to a complete denial of service on the AD DC. The DoS affects all other services as "rpcecho" runs in the main RPC task.
Other sources
Calls to the rpcecho server on the AD DC can request that the server block for a user-defined amount of time, denying service. One RPC function provided by "rpcecho" can block, essentially indefinitely, and because the "rpcecho" service is provided from the main RPC task, which has only one worker, this denies essentially all service on the AD DC.
https://bugzilla.samba.org/showbug.cgi?id=15474
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability ID for rpcecho development server Denial of Service vulnerability?
The vulnerability ID for rpcecho development server Denial of Service vulnerability is CVE-2023-42669.
What is the impact of the rpcecho development server Denial of Service vulnerability?
The rpcecho development server Denial of Service vulnerability can lead to a Denial of Service attack on the Active Directory Domain Controller (AD DC).
Which software is affected by the rpcecho development server Denial of Service vulnerability?
The samba package versions 2:4.15.13+dfsg-0ubuntu0.20.04.6, 2:4.15.13+dfsg-0ubuntu1.5, and 2:4.17.7+dfsg-1ubuntu2.3 are affected by the rpcecho development server Denial of Service vulnerability.
How can I fix the rpcecho development server Denial of Service vulnerability?
To fix the rpcecho development server Denial of Service vulnerability, update the samba package to version 2:4.15.13+dfsg-0ubuntu0.20.04.6, 2:4.15.13+dfsg-0ubuntu1.5, or 2:4.17.7+dfsg-1ubuntu2.3, depending on the affected version.
Where can I find more information about the rpcecho development server Denial of Service vulnerability?
You can find more information about the rpcecho development server Denial of Service vulnerability on the MITRE CVE website, Samba website, and the Ubuntu Security Notices website.