Samba SMB2 Packet Signing bypass enables MITM
CVE-2023-3347 Published on July 20, 2023

Samba: smb2 packet signing is not enforced when "server signing = required" is set
A vulnerability was found in Samba's SMB2 packet signing mechanism. The SMB2 packet signing is not enforced if an admin configured "server signing = required" or for SMB2 connections to Domain Controllers where SMB2 packet signing is mandatory. This flaw allows an attacker to perform attacks, such as a man-in-the-middle attack, by intercepting the network traffic and modifying the SMB2 messages between client and server, affecting the integrity of the data.

Vendor Advisory Vendor Advisory NVD

Vulnerability Analysis

CVE-2023-3347 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
NONE

Timeline

Reported to Red Hat.

Made public. 6 days later.

Weakness Types

Improper Verification of Cryptographic Signature

The software does not verify, or incorrectly verifies, the cryptographic signature for data.

Improper Enforcement of Message Integrity During Transmission in a Communication Channel

The software establishes a communication channel with an endpoint and receives a message from that endpoint, but it does not sufficiently ensure that the message was not modified during transmission. Attackers might be able to modify the message and spoof the endpoint by interfering with the data as it crosses the network or by redirecting the connection to a system under their control.


Products Associated with CVE-2023-3347

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2023-3347 are published in these products:

Canonical Ubuntu Linux
 
Samba
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Storage
 
Fedora Project Fedora
 

Affected Versions

Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Storage 3:

Exploit Probability

EPSS
0.42%
Percentile
61.42%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.