#VU49039 OS Command Injection in xstream - CVE-2020-26217

Vulnerability identifier: #VU49039

Vulnerability risk: Medium

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:Green]

CVE-ID: CVE-2020-26217

CWE-ID: CWE-78

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
xstream
Universal components / Libraries / Libraries used by multiple products

Vendor: XStream

Description

The vulnerability allows a remote user to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation, when processing blacklists. A remote user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

xstream: 1.4.1 - 1.4.13

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External links
https://github.com/x-stream/xstream/commit/0fec095d534126931c99fd38e9c6d41f5c685c1a
https://github.com/x-stream/xstream/security/advisories/GHSA-mw36-7c6c-q4q2
https://lists.debian.org/debian-lts-announce/2020/12/msg00001.html
https://www.debian.org/security/2020/dsa-4811
https://x-stream.github.io/CVE-2020-26217.html

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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.