Sonatype Nexus Repository 3 Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been introduced in Sonatype Nexus Repository 3 due to a regression in version 3.83.0. This issue affects user-uploaded content served from repositories, where a security header is no longer applied. An authenticated attacker with repository upload privileges could exploit this vulnerability, potentially leading to privilege escalation.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, with the possibility of privilege escalation on the Nexus Repository instance.

Remediation

Users are advised to upgrade to Sonatype Nexus Repository version 3.87.0 or later. If an immediate upgrade is not possible, temporary mitigations include setting the Content Disposition in repository settings to 'attachment' or configuring a reverse proxy to add the Content-Security-Policy sandbox header for content served from '/repository/' paths.