PT-2020-6431 · Nextcloud+1 · Nextcloud Desktop Client+1

Carl Pearson + 1 · Published 2020-06-20 · Updated 2023-08-30 · CVE-2021-22895

Positive Technologies (AI Summary)

CVSS v3.1

5.9

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Name of the Vulnerable Software and Affected Versions Nextcloud Desktop Client versions prior to 3.3.1

Description The issue is related to the lack of SSL certificate verification when using the "Register with a Provider" flow in the Nextcloud Desktop Client, allowing a remote attacker to impact data integrity.

Recommendations For versions prior to 3.3.1, update to version 3.3.1 or later to resolve the issue. As a temporary workaround, consider disabling the "Register with a Provider" flow until a patch is available. Restrict access to the affected flow to minimize the risk of exploitation.

Exploit

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

ALT-PU-2023-2019

ALT-PU-2023-4584

ALT-PU-2023-5197

BDU:2021-04668

CVE-2021-22895

DSA-4974-1

GHSA-QPGP-VF4P-WCW5

MGASA-2021-0421

Affected Products

Alt Linux

Nextcloud Desktop Client

References · 20

• 🔥 https://hackerone.com/reports/903424 · Exploit
• https://github.com/nextcloud/desktop/pull/2926 · Patch
• https://osv.dev/vulnerability/DSA-4974-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-22895 · Security Note
• https://advisories.mageia.org/MGASA-2021-0421.html · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-22895 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-22895 · Vendor Advisory
• https://security-tracker.debian.org/tracker/source-package/nextcloud-desktop · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-22895 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-22895 · Vendor Advisory
• https://debian.org/security/2021/dsa-4974 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-04668 · Security Note
• https://osv.dev/vulnerability/MGASA-2021-0421 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-22895 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-22895 · Security Note