SB2020091501 - Gentoo update for Nextcloud Desktop Sync client

Description

This security bulletin contains information about 3 vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2020-8189)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear

The vulnerability allows a remote authenticated user to read and manipulate data.

A cross-site scripting error in Nextcloud Desktop client 2.6.4 allowed to present any html (including local links) when responding with invalid data on the login attempt.

2) Code Injection (CVE-ID: CVE-2020-8224)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: 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:U/U:Green

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

The vulnerability exists due to improper input validation when processing OpenSSL configuration file. A remote user can upload a malicious OpenSSL config file into a fixed directory and execute arbitrary code on the system.

3) Path traversal (CVE-ID: CVE-2020-8227)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote privileged user to execute arbitrary code.

Missing sanitization of a server response in Nextcloud Desktop Client 2.6.4 for Linux allowed a malicious Nextcloud Server to store files outside of the dedicated sync directory.

Remediation

Install update from vendor's website.

References

• https://security.gentoo.org/
• https://security.gentoo.org/glsa/202009-09