Nextcloud
CVE-2023-23943
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V4 - API and Web Service URL allowlisting, SSRF prevention
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Credential Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 4.3 (MEDIUM). Attack characteristics: adjacent network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to make the server perform requests to unintended internal or external resources. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Nextcloud mail is an email app for the nextcloud home server platform. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Validate and allowlist destination URLs, block requests to internal networks, use network segmentation.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Server-Side Request Forgery (SSRF) (CWE-918), which allows attackers to make the server perform requests to unintended internal or external resources. 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. Affected products include: Nextcloud Mail.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
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.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Server-Side Request Forgery exploits applications that fetch remote resources based on user-supplied URLs.
Affected Products (CPE)NVD
Nextcloud server is an open source home cloud implementation. Rated high severity (CVSS 8.8), this vulnerability is remo
A too lax check in Nextcloud Talk 6.0.4, 7.0.2 and 8.0.7 allowed a code injection when a not correctly sanitized talk co
Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Rated critical severity (CVSS 9.8),
Unauthenticated OS command injection in the Collabora Online Built-in CODE Server Nextcloud app (richdocumentscode) befo
Unauthenticated vector-store tampering in Nextcloud MCP Server before 0.117.2 lets any network attacker who can reach th
Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9 suffer from SMB User Authenti
NextCloud Cookbook is a recipe library app. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable,
Nextcloud server is an open source home cloud implementation. Rated high severity (CVSS 8.8), this vulnerability is remo
Nextcloud Desktop Client prior to 3.1.3 is vulnerable to resource injection by way of missing validation of URLs, allowi
lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution vi
Authorization bypass in Windmill 1.56.0-1.614.0 enables Operator role users to escalate privileges to remote code execut
Insufficient protection of the server-side encryption keys in Nextcloud Server 19.0.1 allowed an attacker to replace the
Exploit-DB