SB2017060226 - Amazon Linux AMI update for samba
Published: June 2, 2017 Updated: March 30, 2023
Security Bulletin ID
SB2017060226
Severity
Medium
Patch available
YES
Number of vulnerabilities
4
Exploitation vector
Adjecent network
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Race condition (CVE-ID: CVE-2017-2619)
The vulnerability allows a remote authenticated user to access otherwise restricted files.The vulnerability exists due to a race condition when processing symlinks, which lead to files outside the shared folder. An attacker with ability to crate a symlink on a network share can access files not exported under the share definition.
Successful exploitation of the vulnerability may allow an attacker to gain access to potentially sensitive data, but requires that server is under heavy load.
2) Buffer overflow (CVE-ID: CVE-2016-2126)
The vulnerability allows a remote authenticated attacker to escalate privileges.The vulnerability exists due to a boundary error within Kerberos PAC validation process in winbindd. A remote authenticated attacker can send a specially crafted request to vulnerable Samba server, trigger buffer overflow and execute arbitrary code on the server with elevated privileges.
Successful exploitation of the vulnerability may allow an attacker to execute arbitrary code with elevated privileges.
3) Improper authentication (CVE-ID: CVE-2016-2125)
The vulnerability allows a remote attacker on the local network to bypass Kerberos authentication.The vulnerability exists due to design error when implementing Kerberos authentication. An attacker with access to local network can place a fake Samba server, intercept a valid general purpose Kerberos "Ticket Granting Ticket" (TGT) and fully impersonate the authenticated user or service.
Successful exploitation of the vulnerability may allow an attacker to bypass authentication process and gain access to otherwise restricted resources and services.
4) Insecure library loading (CVE-ID: CVE-2017-7494)
The vulnerability allows a remote authenticated attacker to execute arbitrary code on vulnerable server.The vulnerability exists due to insecure library loading mechanism, when processing files on file shares. A remote attacker with ability to upload file on SMB share can upload and execute arbitrary shared library on the server with privileges of the Samba process.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
Remediation
Install update from vendor's website.