Security restrictions bypass in dropbear (Alpine package)

Published: 2019-03-01

Risk	Low
Patch available	YES
Number of vulnerabilities	1
CVE-ID	CVE-2018-20685
CWE-ID	CWE-284
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	dropbear (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) Security restrictions bypass

EUVDB-ID: #VU16946

Risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-20685

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The vulnerability exists due to improper validation of filenames by the scp.c source code file in the SCP client . A remote unauthenticated attacker can trick the victim into accessing a file with the filename of . or an empty filename from an attacker-controlled Secure Shell (SSH) server to bypass access restrictions on the system, which could be used to conduct further attacks.

Mitigation

Install update from vendor's website.

Vulnerable software versions

dropbear (Alpine package): 2018.76-r2 - 2019.78-r0

CPE2.3

External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.