SB2021121658 - Cleartext transmission of sensitive information in Linux kernel
Published: December 16, 2021
Security Bulletin ID
SB2021121658
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Cleartext transmission of sensitive information (CVE-ID: CVE-2021-45100)
The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.
The ksmbd server through 3.4.2, as used in the Linux kernel through 5.15.8, sometimes communicates in cleartext even though encryption has been enabled. This occurs because it sets the SMB2_GLOBAL_CAP_ENCRYPTION flag when using the SMB 3.1.1 protocol, which is a violation of the SMB protocol specification. When Windows 10 detects this protocol violation, it disables encryption.
Remediation
Install update from vendor's website.