Privilege escalation in Zsh
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2019-20044 |
| CWE-ID | CWE-273 |
| Exploitation vector | Local |
| Public exploit | Public exploit code for vulnerability #1 is available. |
| Vulnerable software Subscribe |
zsh Client/Desktop applications / Software for system administration |
| Vendor | SourceForge |
Security Bulletin
This security bulletin contains one low risk vulnerability.
1) Improper Check for Dropped Privileges
EUVDB-ID: #VU26210
Risk: Low
CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2019-20044
CWE-ID:
CWE-273 - Improper Check for Dropped Privileges
Exploit availability: Yes
DescriptionThe 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.
Install updates from vendor's website.
Vulnerable software versionszsh: 5.0.0 - 5.7.1
External linkshttp://zsh.sourceforge.net/releases.html
http://github.com/XMB5/zsh-privileged-upgrade
http://lists.debian.org/debian-lts-announce/2020/03/msg00004.html
http://www.zsh.org/mla/zsh-announce/141
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
