An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.

A vulnerability in Zammad v5.3.0 allows attackers to execute arbitrary code or escalate privileges via a crafted message sent to the server.

An access control issue in Zammad v5.0.3 allows attackers to write entries to the CTI caller log without authentication. This vulnerability can allow attackers to execute phishing attacks or cause a Denial of Service (DoS).

In Zammad 6.4.x before 6.4.2, there is client-side enforcement of server-side security. When changing their two factor authentication configuration, users need to re-authenticate with their current password first. However, this change was enforced in Zammad only on the front end level, and not when using the API directly.

An issue was discovered in Zammad before 6.3.0. Users with customer access to a ticket could have accessed time accounting details of this ticket via the API. This data should be available only to agents.

In Zammad 6.4.x before 6.4.2, there is information exposure. Only agents should be able to see and work on shared article drafts. However, a logged in customer was able to see details about shared drafts for their customer tickets in the browser console, which may contain confidential information, and also to manipulate them via API.

With certain LDAP configurations, Zammad 5.0.1 was found to be vulnerable to unauthorized access with existing user accounts.

An SSRF issue was discovered in Zammad before 3.4.1. The SMS configuration interface for Massenversand is implemented in a way that renders the result of a test request to the User. An attacker can use this to request any URL via a GET request from the network interface of the server. This may lead to disclosure of information from intranet systems.

An issue was discovered in Zammad before 3.5.1. A REST API call allows an attacker to change Ticket Article data in a way that defeats auditing.

Incorrect Access Control in Zammad 1.0.x up to 4.0.0 allows attackers to obtain sensitive information via email connection configuration probing.

An issue was discovered in Zammad 3.0 through 3.2. The WebSocket server crashes when messages in non-JSON format are sent by an attacker. The message format is not properly checked and parsing errors not handled. This leads to a crash of the service process.

An issue was discovered in Zammad 3.0 through 3.2. It does not prevent caching of confidential data within browser memory. An attacker who either remotely compromises or obtains physical access to a user's workstation can browse the browser cache contents and obtain sensitive information. The attacker does not need to be authenticated with the application to view this information, as it would be available via the browser cache.

A lack of password length restriction in Zammad v5.1.0 allows for the creation of extremely long passwords which can cause a Denial of Service (DoS) during password verification.

A lack of rate limiting in the 'forgot password' feature of Zammad v5.1.0 allows attackers to send an excessive amount of reset requests for a legitimate user, leading to a possible Denial of Service (DoS) via a large amount of generated e-mail messages.

An issue was discovered in Zammad before 6.2.0. Due to lack of rate limiting in the "email address verification" feature, an attacker could send many requests for a known address to cause Denial Of Service (generation of many emails, which would also spam the victim).

In Zammad before 6.3.1, a Ruby gem bundled by Zammad is installed with world-writable file permissions. This allowed a local attacker on the server to modify the gem's files, injecting arbitrary code into Zammad processes (which run with the environment and permissions of the Zammad user).

An issue was discovered in Zammad before 6.3.0. An authenticated agent could perform a remote Denial of Service attack by calling an endpoint that accepts a generic method name, which was not properly sanitized against an allowlist.

Zammad 5.3.x (Fixed 5.4.0) is vulnerable to Incorrect Access Control. An authenticated attacker could gain information about linked accounts of users involved in their tickets using the Zammad API.

Zammad before 3.3.1, when Domain Based Assignment is enabled, relies on a claimed e-mail address for authorization decisions. An attacker can register a new account that will have access to all tickets of an arbitrary Organization.

An issue was discovered in Zammad 3.0 through 3.2. It allows for users to view ticket customer details associated with specific customers. However, the application does not properly implement access controls related to this functionality. As such, users of one company are able to access ticket data from other companies. Due to the multi-tenant nature of this application, users who can access ticket details from one organization to the next allows for users to exfiltrate potentially sensitive data of other companies.

An issue was discovered in Zammad before 3.4.1. There are wrong authorization checks for impersonation requests via X-On-Behalf-Of. The authorization checks are performed for the actual user and not the one given in the X-On-Behalf-Of header.

Zammad 5.3.x (Fixed in 5.4.0) is vulnerable to Incorrect Access Control. An authenticated attacker with agent and customer roles could perform unauthorized changes on articles where they only have customer permissions.

An issue in Zammad v5.4.0 allows attackers to bypass e-mail verification using an arbitrary address and manipulate the data of the generated user. Attackers are also able to gain unauthorized access to existing tickets.

Cross Site Scripting (XSS) in Zammad 1.0.x up to 4.0.0 allows remote attackers to execute arbitrary web script or HTML via the User Avatar attribute.

Cross Site Scripting (XSS) in Zammad 1.0.x up to 4.0.0 allows remote attackers to execute arbitrary web script or HTML via multiple models that contain a 'note' field to store additional information.

Zammad GmbH Zammad 2.3.0 and earlier is affected by: Cross Site Scripting (XSS) - CWE-80. The impact is: Execute java script code on users browser. The component is: web app. The attack vector is: the victim must open a ticket. The fixed version is: 2.3.1, 2.2.2 and 2.1.3.

An issue was discovered in Zammad before 6.2.0. In several subsystems, SSL/TLS was used to establish connections to external services without proper validation of hostname and certificate authority. This is exploitable by man-in-the-middle attackers.

An issue was discovered in Zammad before 3.4.1. The Tag and Link REST API endpoints (for add and delete) lack a CSRF token check.

In Zammad before 3.3.1, a Customer has ticket access that should only be available to an Agent (e.g., read internal data, split, or merge).

An issue was discovered in Zammad before 3.4.1. There is Stored XSS via a Tags element in a TIcket.