CVE-2023-23943

Public Exploit
Blind SSRF via server URL input in the Nextcloud Mail app

Description

Nextcloud mail is an email app for the nextcloud home server platform. In affected versions the SMTP, IMAP and Sieve host fields allowed to scan for internal services and servers reachable from within the local network of the Nextcloud Server. It is recommended that the Nextcloud Maill app is upgraded to 1.15.0 or 2.2.2. The only known workaround for this issue is to completely disable the nextcloud mail app.

Category

5.0
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.35%
Vendor Advisory github.com
Affected: nextcloud security-advisories
Published at:
Updated at:

References

Link Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8gcx-r739-9pf6 vendor advisory
https://github.com/nextcloud/mail/pull/7796 patch
https://hackerone.com/reports/1736390 third party advisory exploit
https://hackerone.com/reports/1741525 third party advisory exploit
https://hackerone.com/reports/1746582 third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2023-23943?
CVE-2023-23943 has been scored as a medium severity vulnerability.
How to fix CVE-2023-23943?
To fix CVE-2023-23943, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-23943 being actively exploited in the wild?
It is possible that CVE-2023-23943 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-23943?
CVE-2023-23943 affects nextcloud security-advisories.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.