Horizon Alert
Summary of the vulnerability and why it matters
This advisory concerns a vulnerability in Etherpad, a real-time collaborative editing tool. The issue allows malicious code to be injected and executed when users, including administrators, access a compromised document or a timeslider view. While the primary concern is confirming relevance and exposure, this type of vulnerability could potentially lead to unauthorized actions within the application.
- Malicious code can run via shared documents.
- Protects collaborative editing environments from attack.
- Confirm relevance to our deployed collaboration tools.
Attack Path
How an attacker could exploit the issue
An attacker can exploit this vulnerability by creating a malicious Etherpad document containing specially crafted markup. When another user, including an administrator, opens this document or accesses the timeslider, the embedded malicious markup can execute as cross-site scripting. This could lead to the theft of sensitive information or unauthorized actions within the application.
- Entry condition: Write access to a pad.
- Trigger point: Opening a malicious pad or timeslider.
- Resulting risk: Sensitive information theft and unauthorized actions.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability could allow a malicious user to inject harmful scripts into Etherpad documents. When another user, including an administrator, opens a compromised pad or accesses the timeslider, these scripts could execute in their browser.
- Pad content and user sessions at risk.
- Malicious markup can be stored in pads.
- Unauthorized actions and data compromise may occur.
Operational Fix
Recommended remediation, mitigation, and detection steps
Application owners and platform teams are likely responsible for addressing this cross-site scripting vulnerability in Etherpad, as it affects user-accessible pads and administrative interfaces. The immediate first step is to identify all instances of Etherpad within the environment, assess their exposure and business criticality, and confirm the accountable owner for each. Remediation planning should then be based on this risk assessment.
- Application owners should manage the issue.
- Verify Etherpad instances and exposure.
- Plan remediation based on risk assessment.
