TI-2023-09741 Aliases CVE-2023-23943

Blind SSRF via server URL input in the Nextcloud Mail app

MEDIUM 56CWE-918Published 2023-02-06 · Updated 2025-03-10

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-918 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00919 60th percentileScored 2026-11-07

Public exploit Yes 3 exploit referencesTagged by NVD

Fix Fixed security-advisories (nextcloud): 2.2.2, 1.15.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
nextcloud	security-advisories	2.0.0 to before 2.2.2; before 1.15.0	2.2.2, 1.15.0	Patch available	CNA

security-advisories Vendornextcloud Affected 2.0.0 to before 2.2.2; before 1.15.0 Fixed in 2.2.2, 1.15.0 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:nextcloud:mail::::::::	before 1.15.0; 2.2.0 to before 2.2.2	Vulnerable	nextcloud

cpe:2.3:a:nextcloud:mail:*:*:*:*:*:*:*:* Versions before 1.15.0; 2.2.0 to before 2.2.2 Vulnerable ·nextcloud

Remediation

Fix · CNA security-advisories (nextcloud) Fixed in 2.2.2, 1.15.0

Timeline

2026-10-02 Threatist record created from CVE-2023-23943

References

Exploit 3

Patch 1

https://github.com/nextcloud/mail/pull/7796

Advisory 1

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8gcx-r739-9pf6

TI-2022-13176 Unauthenticated SSRF in 3rd party module "cerdic/csstidy" CVSS 3.1CRITICAL 9.8
TI-2023-26170 Nextcloud Mail app vulnerable to Server-Side Request Forgery CVSS 3.1CRITICAL 9.8
TI-2021-12320 Missing permission check on email metadata retrieval CVSS 3.1HIGH 8.8
TI-2024-35179 Nextcloud Mail auto configurator can be tricked into sending account information to wrong servers CVSS 3.1HIGH 8.2
TI-2020-06574 A missing verification of the TLS host in Nextcloud Mail 1.1.3 allowed a man in the middle attack. CVSS 3.1HIGH 7.0
TI-2023-09742 Nexcloud Mail app temporarily stores cleartext password in database CVSS 3.1MEDIUM 6.5

See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences