Resource exhaustion in Samba
CVE-2023-42669
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 "dcesrv_echo_TestSleep()" 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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.019 (79.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 79.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.017 · newest: 0.019 · change: +0.002
Affected products
- Samba
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8 — versions 0:4.18.6-2.el8_9
- Red Hat Enterprise Linux 8.6 Extended Update Support — versions 0:4.15.5-13.el8_6
- Red Hat Enterprise Linux 8.8 Extended Update Support — versions 0:4.17.5-4.el8_8
- Red Hat Enterprise Linux 9 — versions 0:4.18.6-101.el9_3
- Red Hat Enterprise Linux 9.0 Extended Update Support — versions 0:4.15.5-111.el9_0
- Red Hat Enterprise Linux 9.2 Extended Update Support — versions 0:4.17.5-104.el9_2
- Red Hat Storage 3
Weakness classification (CWE)
References
- access.redhat.com/errata/RHSA-2023:6209 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2023:6744 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2023:7371 (vendor-advisory)
- access.redhat.com/errata/RHSA-2023:7408 (vendor-advisory)
- access.redhat.com/errata/RHSA-2023:7464 (vendor-advisory)
- access.redhat.com/errata/RHSA-2023:7467 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2023-42669 (Third Party Advisory, vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Issue Tracking)
- bugzilla.samba.org/show_bug.cgi (Issue Tracking)
- www.samba.org/samba/security/CVE-2023-42669.html (Vendor Advisory)
Frequently asked questions
- What is CVE-2023-42669?
- CVE-2023-42669 is a medium-severity vulnerability in Samba, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2023-11-06.
- How severe is CVE-2023-42669?
- Medium severity. CVSS v3 base score is 6.5 out of 10.