Denial of service

Vulnerability

The OTRS Community Edition and OTRS application contains an improper check for filenames with overly long extensions in the PostMaster (sending email) and file upload functionality. This flaw leads to an endless loop when processing such filenames. Affected versions include OTRS Community Edition 5.0.x up to 5.0.38, 6.0.x up to 6.0.23, and OTRS 7.0.x up to 7.0.12 [1].

Exploitation

A remote attacker can exploit this vulnerability by sending an email or uploading a file with an overly long extension to the affected system. No authentication is required, as the system processes incoming emails or file uploads automatically. The attacker does not need any special privileges; the condition is triggered upon processing the crafted filename.

Impact

Successful exploitation results in an endless loop, causing a denial of service (DoS) condition. The system may become unresponsive or crash, disrupting availability. The attack does not lead to data theft or modification, but the availability of the OTRS instance is compromised.

Mitigation

The vendor has released security updates to address this issue. Users should upgrade to OTRS Community Edition 5.0.39 or later, 6.0.24 or later, or OTRS 7.0.13 or later. For systems running the end-of-life 6.x branch, upgrading to a supported version (e.g., OTRS 7.x) is recommended [1].