Command injection in linux-pam (Alpine package)

Published: 2019-01-10

Risk	Low
Patch available	YES
Number of vulnerabilities	1
CVE-ID	CVE-2018-19788
CWE-ID	CWE-77
Exploitation vector	Local
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software	linux-pam (Alpine package) Operating systems & Components / Operating system package or component
Vendor	Alpine Linux Development Team

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Command injection

EUVDB-ID: #VU16313

Risk: Low

CVSSv4.0: 7.1 [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]

CVE-ID: CVE-2018-19788

CWE-ID: CWE-77 - Command injection

Exploit availability: Yes

Description

The vulnerability allows a local authenticated attacker to execute arbitrary commands on the target system.

The vulnerability exists due to PolicyKit's improper validation of permission requests for any low-privileged user with UID greater than INT_MAX, a constant in computer programming that defines what maximum value an integer variable can store, which equals to 2147483647 (in hexadecimal 0x7FFFFFFF). A local authenticated attacker with a uid greater than INT_MAX can execute any systemctl command.

Mitigation

Install update from vendor's website.

Vulnerable software versions

linux-pam (Alpine package): 0.115-r0 - 1.3.0-r0

CPE2.3

External links

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. However, proof of concept for this vulnerability is available.