Nextcloud
CVE-2023-39957
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Path canonicalization, traversal prevention
MITRE ATT&CK
2 techniques across 2 tactics: Discovery, Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.8 (HIGH). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | A local attacker with access to the system could access files and directories outside the intended path. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Nextcloud Talk Android allows users to place video and audio calls through Nextcloud on Android. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Path Traversal vulnerability could allow attackers to access files and directories outside the intended path.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Validate and canonicalize file paths. Use chroot or sandboxing. Reject input containing path separators or '../' sequences.
Affects your stack
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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 Path Traversal (CWE-22), which allows attackers to access files and directories outside the intended path. Nextcloud Talk Android allows users to place video and audio calls through Nextcloud on Android. Prior to version 17.0.0, an unprotected intend allowed malicious third party apps to trick the Talk Android app into writing files outside of its intended cache directory. Nextcloud Talk Android version 17.0.0 has a patch for this issue. No known workarounds are available. Affected products include: Nextcloud Talk. Version information: version 17.0.0.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Nextcloud Talk Android allows users to place video and audio calls through Nextcloud on Android. Prior to version 17.0.0, an unprotected intend allowed malicious third party apps to trick the Talk Android app into writing files outside of its intended cache directory. Nextcloud Talk Android version 17.0.0 has a patch for this issue. No known workarounds are available.
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
Path traversal exploits occur when applications use user-controlled input to construct file system paths without proper validation.
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