#VU54666 Information disclosure in Nextcloud Mail - CVE-2021-32707

Vulnerability identifier: #VU54666

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-32707

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Nextcloud Mail
Web applications / Modules and components for CMS

Vendor: Nextcloud

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to the affected application does by default not render images in emails to not leak the read state. A remote attacker can gain unauthorized access to sensitive information on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Mail: 1.9.0 - 1.9.5

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External links
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xxp4-44xc-8crh/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.