SB2022030435 - SUSE update for zsh

Description

This security bulletin contains information about 3 vulnerabilities.

1) Stack-based buffer overflow (CVE-ID: CVE-2018-1100)

CWE-ID: CWE-121 - Stack-based buffer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local attacker to gain elevated privileges on the target system.

The vulnerability exists due to stack-based buffer overflow in the utils.c:checkmailpath function. A local attacker can trigger memory corruption and execute arbitrary code with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

2) Improper Check for Dropped Privileges (CVE-ID: CVE-2019-20044)

CWE-ID: CWE-273 - Improper Check for Dropped Privileges

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to Zsh fails to overwrite the saved uid, so the original privileges, dropped by the --no-PRIVILEGED option, can be restored by executing MODULE_PATH=/dir/with/module zmodload with a module that calls setuid(). A local user can execute arbitrary commands on the system with elevated privileges.

3) OS Command Injection (CVE-ID: CVE-2021-45444)

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to recursive PROMPT_SUBST expansion when processing malicious output. A remote attacker with ability to control the output can inject and execute arbitrary commands on the system with privileges on the current user.

Remediation

Install update from vendor's website.

References

• https://www.suse.com/support/update/announcement/2022/suse-su-20220733-1/