CVE-2021-45100 : What You Need to Know
Learn about CVE-2021-45100 affecting the ksmbd server in the Linux kernel, allowing cleartext communication despite encryption. Discover mitigation steps and necessary updates.
This CVE-2021-45100 article provides details about a vulnerability in the ksmbd server affecting the Linux kernel.
Understanding CVE-2021-45100
CVE-2021-45100 involves a security issue in the ksmbd server that leads to communication in cleartext despite encryption being enabled.
What is CVE-2021-45100?
The ksmbd server, up to version 3.4.2 and part of the Linux kernel up to version 5.15.8, can communicate in cleartext due to setting the SMB2_GLOBAL_CAP_ENCRYPTION flag incorrectly.
The Impact of CVE-2021-45100
Windows 10 can disable encryption upon detecting this violation, potentially exposing sensitive data to interception.
Technical Details of CVE-2021-45100
CVE-2021-45100 manifests in the following technical aspects:
Vulnerability Description
The vulnerability arises from setting the SMB2_GLOBAL_CAP_ENCRYPTION flag improperly during SMB 3.1.1 protocol usage.
Affected Systems and Versions
- ksmbd server versions up to 3.4.2
- Linux kernel versions up to 5.15.8
Exploitation Mechanism
The incorrect flag setting allows cleartext communication, compromising data integrity and confidentiality.
Mitigation and Prevention
To address CVE-2021-45100, consider the following:
Immediate Steps to Take
- Update the ksmbd server and Linux kernel to patched versions
- Configure network encryption to mitigate cleartext communication risks
Long-Term Security Practices
- Regularly monitor for security advisories and apply updates promptly
- Implement network encryption best practices to prevent data exposure
Patching and Updates
- Apply official patches for the ksmbd server and the Linux kernel to resolve the encryption issue