#VU23393 Missing Authentication for Critical Function in Shadowsocks-libev - CVE-2019-5164

Vulnerability identifier: #VU23393

Vulnerability risk: High

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

CVE-ID: CVE-2019-5164

CWE-ID: CWE-306

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Shadowsocks-libev
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Shadowsocks

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to an insufficient authentication mechanism in the ss-manager binary. A remote authenticated attacker can send a specially crafted network packets to ss-manager, cause an arbitrary binary to run and execute arbitrary code on the target system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Shadowsocks-libev: 3.3.2 - 3.3.3

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External links
https://talosintelligence.com/vulnerability_reports/TALOS-2019-0958

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