CVE-2022-38023
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Description
A flaw was found in samba. The Netlogon RPC implementations may use the rc4-hmac encryption algorithm, which is considered weak and should be avoided even if the client supports more modern encryption types. This issue could allow an attacker who knows the plain text content communicated between the samba client and server to craft data with the same MD5 calculation and replace it without being detected.
Mitigation
Users can disable MD5-based NetLogon by adding the following snippet to their smb.conf
reject md5 clients = yes
in case there's still need to allow SMB to authenticate to MD5-based NetLogon servers, it's possible to explicitly
enable it per-server based:
server reject md5 schannel:<SERVERNAME>$ = no
Additional information
- Bugzilla 2154362: samba: RC4/HMAC-MD5 NetLogon Secure Channel is weak and should be avoided
- CWE-328: Use of Weak Hash
- FAQ: Frequently asked questions about CVE-2022-38023
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
| Red Hat | NVD | |
|---|---|---|
CVSS v3 Base Score | 8.1 | 8.1 |
Attack Vector | Network | Network |
Attack Complexity | High | High |
Privileges Required | None | None |
User Interaction | None | None |
Scope | Unchanged | Unchanged |
Confidentiality Impact | High | High |
Integrity Impact | High | High |
Availability Impact | High | High |
CVSS v3 Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
What can I do if my product is listed as "Will not fix"?
What can I do if my product is listed as "Fix deferred"?
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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