Nextcloud: User with read-only access to a share can gain write access to sub-folders in the share

user0 creates folders /test and /test/sub user0 creates file /test/sub/file.txt user0 shares folder /test with user1 with read+share permissions 17 user1 receives the folder /test and can read-download /test/sub/file.txt - good user1 creates a link share of /test/sub - it has permissions 1...

Nextcloud: Reflected XSS / Markup Injection in `index.php/svg/core/logo/logo` parameter `color`

I just found a reflected Cross-Site Scripting XSS vulnerability in Nextcloud Server that affects current stable and dates back to at least 15.0.5. The vulnerability seems mitigated by a Content-Security-Policy CSP, but there might be a residual risk for phishing, due to the CSP's lack of a...

Extract add-on for Nextcloud OS Command Injection Vulnerability

Extract add-on for Nextcloud is a set of component applications for Netcloud. An input validation vulnerability exists in Extract add-on for Nextcloud lib/Controller/ExtractionController.php, which allows remote attackers to submit a special request that can be used to execute arbitrary OS comman...

Nextcloud Extract App OS Command Injection Vulnerability

Nextcloud is an open source self-hosted file synchronization and sharing communication application platform from Nextcloud, Germany.Extract App is one of the compressed file extractor. An operating system command injection vulnerability exists in Nextcloud Extract App versions prior to 1.2.0. The...

CVE-2019-12739

lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution via shell metacharacters in a RAR filename via ajax/extractRar.php nameOfFile and directory parameters...

CVE-2019-12739

lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution via shell metacharacters in a RAR filename via ajax/extractRar.php nameOfFile and directory parameters...

Remote code execution

lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution via shell metacharacters in a RAR filename via ajax/extractRar.php nameOfFile and directory parameters...

CVE-2019-12739

The CVE-2019-12739 entry concerns the Nextcloud Extract add-on: lib/Controller/ExtractionController.php vulnerable before version 1.2.0. It allows Remote Code Execution via shell metacharacters in a RAR filename passed through ajax/extractRar.php (nameOfFile and directory parameters). Affected co...

CVE-2019-12739

lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution via shell metacharacters in a RAR filename via ajax/extractRar.php nameOfFile and directory parameters...

Nextcloud: Non-admin users can trigger writes to memcached by entering a malicious server as a share URL

Dangling remote share attempts in Nextcloud 16 allow a DNS pollution when running long...

Nextcloud: Linux client is vulnerable to directory traversal when downloading files

Summary The Nextcloud Linux client is vulnerable to directory traversal when downloading files from a Nextcloud server. A malicious Nextcloud administrator can exploit the vulnerability to write arbitrary files to a user computers with the potential for remote command execution under certain...

Nextcloud: Memory Leak in OCUtil.dll library in Desktop client can lead to DoS

The function IsChildFileconst wchart rootFolder, const wchart file in FileUtil.cpp allocates memory on line 42 and fails to free it. The following PoC code can provide evidence. The code and the PoC executable is attached to this report. Also OCUtils.dll and OCUtilsx64.dll library which is...

Nextcloud: Vulnerable W3 Total Cache plugin version in use on nextcloud.com

Hi there, I noticed you are currently using a vulnerable version of W3 Total Cache, as the changelog containing the plugin version is publicly reachable: https://nextcloud.com/wp-content/plugins/w3-total-cache/changelog.txt W3 Total Cache makes the site vulnerable to a series of attacks, includin...

Nextcloud: Blind Stored XSS on iOS App due to Unsanitized Webview

Hi Team! I found a Blind XSS can executed on iOS App due to unsanitized webview. Using this issue, attacker can extract information from victim. Steps To Reproduce: 1. Upload malicious HTML, share to victim 2. Waiting victim to open it F487447 F487448 HTML payload attached, don't forget to change...

Nextcloud: W3 Total Cache plugin multiple vulnerabilities

W3 Total Cache plugin version = 0.9.4.1 on the https://nextcloud.com has multiple vulnerabilities. See the screenshot.png Impact Remote Command Execution, Unauthenticated Security Token Bypass, Unauthenticated Arbitrary File Read etc...

Nextcloud: External Storage - WebDAV - New user has access to storage from deleted user (same user-ID)

Delete existing user account "user3" Create new user account "user3" Also reported on https://github.com/nextcloud/server/issues/15258 Impact Newly created user with same user-id of a deleted user has access to the configured external webdav storage from the deleted user...

Nextcloud: Remote Code Execution via Extract App Plugin

Hi, I found a critical issue in the Add-on "Extract" listed in the Nextcloud Marketplace: https://apps.nextcloud.com/apps/extract This extension can be installed directly from Nextcloud Application The vulnerability was found in file: extract/lib/Controller/ExtractionController.php line 102. The...

Nextcloud: Combination of content provider allows private data disclosure

Good afternoon. Sorry, its me again .. I use NC on a daily basis so I often makes some checks .. As per 489105, document thumbnail shall not be disclosed. The exposure on thumbnailCache/ is an already know issue. However, malicious apps are still able to extract at least pictures and text files b...

Nextcloud: In Dockerized Environments, Failing to Read config.php Grants Any Anonymous User Full Admin Access

Consider this deployment: - Nextcloud is already installed in a Dockerized environment. - There are two Nextcloud containers running in the environment. - Both containers share the same MySQL database. - Both containers share the same data /var/www/html/data and config /var/www/html/config via...

2FA sessions not properly expired on password change (NC-SA-2020-001)

A bug in Nextcloud Server 15.0.2 causes pending 2FA logins to not be correctly expired when the password of the user is reset...