SB2021051027 - Amazon Linux AMI update for exim
Published: May 10, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Input validation error (CVE-ID: CVE-2020-28015)
The vulnerability allows a local user to bypass implemented security restrictions
The vulnerability exists due to insufficient validation of user-supplied input when processing new line characters. A local user can inject a new line character into spool header file and execute arbitrary commands.
2) Integer overflow (CVE-ID: CVE-2020-28017)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow within the receive_add_recipient() function. A remote attacker can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
3) Use-after-free (CVE-ID: CVE-2020-28018)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in tls-openssl.c. A remote non-authenticated attacker can send specially crafted data to the mail server, trigger a use-after-free error and execute arbitrary code on the system with root privileges.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
4) Input validation error (CVE-ID: CVE-2020-28021)
The vulnerability allows a remote attacker to bypass implemented security restrictions
The vulnerability exists due to insufficient validation of user-supplied input when processing new line characters. A remote attacker can inject a new line character into the spool header file and modify the mail queue.
Remediation
Install update from vendor's website.