In Zammad 6.4.x before 6.4.2, SSRF can occur. Authenticated admin users can enable webhooks in Zammad, which are triggered as POST requests when certain conditions are met. If a webhook endpoint returned a redirect response, Zammad would follow it automatically with another GET request. This could be abused by an attacker to cause GET requests for example in the local network.

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.

In Zammad 6.4.x before 6.4.2, an authenticated agent with knowledge base permissions was able to use the Zammad API to fetch knowledge base content that they have no permission for.

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.

Zammad before 6.4.1 places sensitive data (such as authmicrosoftoffice365credentials and applicationsecret) in log files.

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. 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.

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.

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).

An issue was discovered in Zammad before 6.2.0. When listing tickets linked to a knowledge base answer, or knowledge base answers of a ticket, a user could see entries for which they lack permissions.

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 6.2.0. It uses the public endpoint /api/v1/signshow for its login screen. This endpoint returns internal configuration data of user object attributes, such as selectable values, which should not be visible to the public.

An issue was discovered in Zammad before 6.2.0. An attacker can trigger phishing links in generated notification emails via a crafted first or last name.

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.

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 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.

Insufficient privilege verification in Zammad v5.3.0 allows an authenticated attacker to perform changes on the tags of their customer tickets using the Zammad API. This is now corrected in v5.3.1 so that only agents with write permissions may change ticket tags.

An issue in the component /api/v1/mentions of Zammad v5.3.0 allows authenticated attackers with agent permissions to view information about tickets they are not authorized to see.

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

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 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).

An access control issue in Zammad v5.0.3 broadcasts administrative configuration changes to all users who have an active application instance, including settings that should only be visible to authenticated users.

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

In Zammad 5.0.2, agents can configure "out of office" periods and substitute persons. If the substitute persons didn't have the same permissions as the original agent, they could receive ticket notifications for tickets that they have no access to.

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.

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

Text injection/Content Spoofing in 404 page in Zammad 1.0.x up to 4.0.0 could allow remote attackers to manipulate users into visiting the attackers' page.

Incorrect Access Control in Zammad 1.0.x up to 4.0.0 allows remote attackers to obtain sensitive information via the Ticket Article detail view.

Incorrect Access Control for linked Tickets in Zammad 1.0.x up to 4.0.0 allows remote attackers to obtain sensitive information.