PT-2023-5260 · Nextcloud+2 · Nextcloud Server+2

Mikaelgundersen · Published 2023-08-10 · Updated 2025-01-24 · CVE-2023-39958

Positive Technologies (AI Summary)

CVSS v3.1

5.8

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Name of the Vulnerable Software and Affected Versions Nextcloud Server versions 22.0.0 through 22.2.10.12 Nextcloud Server versions 23.0.0 through 23.0.12.7 Nextcloud Server versions 24.0.0 through 24.0.12.4 Nextcloud Server versions 25.0.0 through 25.0.8 Nextcloud Server versions 26.0.0 through 26.0.3

Description The issue is related to missing protection in Nextcloud Server, allowing an attacker to brute force the client secrets of configured OAuth2 clients. This can be exploited by a remote attacker to enumerate secret data of configured OAuth2 clients due to improper rate limiting of authentication attempts.

Recommendations For Nextcloud Server versions 22.0.0 through 22.2.10.12, update to version 22.2.10.13 or later. For Nextcloud Server versions 23.0.0 through 23.0.12.7, update to version 23.0.12.8 or later. For Nextcloud Server versions 24.0.0 through 24.0.12.4, update to version 24.0.12.5 or later. For Nextcloud Server versions 25.0.0 through 25.0.8, update to version 25.0.9 or later. For Nextcloud Server versions 26.0.0 through 26.0.3, update to version 26.0.4 or later.

Exploit

Fix

Improper Restriction of Excessive Authentication Attempts

Weakness Enumeration

CWE-307

Related Identifiers

ALT-PU-2023-7785

ALT-PU-2025-1855

BDU:2023-05877

CVE-2023-39958

GHSA-VV27-G2HQ-V48H

Affected Products

Alt Linux

Nextcloud Server

Red Os

References · 10

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39958.json · Exploit
• https://github.com/nextcloud/server/pull/38773 · Vendor Advisory
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vv27-g2hq-v48h · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2023-39958 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2023-39958 · Security Note
• https://bdu.fstec.ru/vul/2023-05877 · Security Note
• https://redos.red-soft.ru/support/secure · Note
• https://redos.red-soft.ru/support/secure/uyazvimosti/support/secure/uyazvimosti/mnozhestvennye-uyazvimosti-nextcloud-cve-2023-39958-cve-2023-39959-cve-2023-39962-cve-2023-39963-cve · Note
• https://twitter.com/VulmonFeeds/status/1689739911832707072 · Twitter Post
• https://hackerone.com/reports/1258448 · Note