#VU103052 Reversible One-Way Hash in Nextcloud Server and Nextcloud Enterprise Server - CVE-2024-52521

Vulnerability identifier: #VU103052

Vulnerability risk: Low

CVSSv4.0: 0.1 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2024-52521

CWE-ID: CWE-328

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Nextcloud Server
Client/Desktop applications / Messaging software
Nextcloud Enterprise Server
Client/Desktop applications / Messaging software

Vendor: Nextcloud

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the MD5 hashes are used to check background jobs for their uniqueness. A remote user can cause potential hash collision for background jobs to skip queuing them.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Server: 28.0.0 - 29.0.6

Nextcloud Enterprise Server: 28.0.0 - 29.0.6

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External links
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-2q6f-gjgj-7hp4
https://github.com/nextcloud/server/pull/47769
https://github.com/nextcloud/server/commit/a933ba1fdba77e7d8c6b8ff400e082cf853ea46d

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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.