Privilege escalation in systemd



Risk Low
Patch available YES
Number of vulnerabilities 2
CVE-ID CVE-2019-3843
CVE-2019-3844
CWE-ID CWE-264
Exploitation vector Local
Public exploit N/A
Vulnerable software
 systemd
Server applications / Other server solutions

Vendor Freedesktop.org

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU18435

Risk: Low

CVSSv4.0: 5.9 [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]

CVE-ID: CVE-2019-3843

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to an error in the process of binary creation, when the DynamicUser property is used to create a SUID or SGID binary for a systemd service. A local user can abuse the systemd functionality to execute arbitrary code on the target system with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

systemd: 200 - 242 rc4

systemd: before

CPE2.3 External links

https://www.securityfocus.com/bid/108116
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3843
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5JXQAKSTMABZ46EVCRMW62DHWYHTTFES/


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.

2) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU24717

Risk: Low

CVSSv4.0: 7.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/U:Clear]

CVE-ID: CVE-2019-3844

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

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

The vulnerability exists due to the systemd service that uses DynamicUser property can get new privileges through the execution of SUID binaries, which would allow to create binaries owned by the service transient group with the setgid bit set. A local user may use this flaw to access resources that will be owned by a potentially different service in the future, when the GID will be recycled.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

systemd: 230 - 242 rc4

CPE2.3 External links

https://www.securityfocus.com/bid/108096
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3844


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.



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