#VU31790 Incorrect default permissions in F5 Networks products - CVE-2020-5906

Vulnerability identifier: #VU31790

Vulnerability risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-5906

CWE-ID: CWE-276

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
BIG-IP
Hardware solutions / Firmware
BIG-IP LTM
Hardware solutions / Security hardware applicances
BIG-IP AFM
Hardware solutions / Security hardware applicances
BIG-IP Analytics
Hardware solutions / Security hardware applicances
BIG-IP APM
Hardware solutions / Security hardware applicances
BIG-IP ASM
Hardware solutions / Security hardware applicances
BIG-IP FPS
Hardware solutions / Security hardware applicances
BIG-IP GTM
Hardware solutions / Security hardware applicances
BIG-IP PEM
Hardware solutions / Security hardware applicances
BIG-IP AAM
Hardware solutions / Routers & switches, VoIP, GSM, etc
BIG-IP DNS
Hardware solutions / Routers & switches, VoIP, GSM, etc
BIG-IP Link Controller
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: F5 Networks

Description

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

The vulnerability exists due to incorrect default permissions for the "scp.blacklist" files. A remote user can read and overwrite blacklisted files via SCP.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

BIG-IP: 11.6.1 - 11.6.5, 12.1.0 - 12.1.5, 13.1.0 - 13.1.3

BIG-IP LTM: 11.6.1 - 13.1.3

BIG-IP AAM: 11.6.1 - 13.1.3

BIG-IP AFM: 11.6.1 - 13.1.3

BIG-IP Analytics: 11.6.1 - 13.1.3

BIG-IP APM: 11.6.1 - 13.1.3

BIG-IP ASM: 11.6.1 - 13.1.3

BIG-IP DNS: 11.6.1 - 13.1.3

BIG-IP FPS: 11.6.1 - 13.1.3

BIG-IP GTM: 11.6.1 - 13.1.3

BIG-IP Link Controller: 11.6.1 - 13.1.3

BIG-IP PEM: 11.6.1 - 13.1.3

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External links
https://support.f5.com/csp/article/K82518062
https://www.kb.cert.org/vuls/id/290915

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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