Mastodon, a social network based on software for servers of the same name, has been found to have a vulnerability that could have allowed attackers to read individual pieces of information. The problem was caused by inadequate filtering of the data transferred during LDAP authentication. The vulnerability allows attackers to smuggle in an LDAP database query, which can be used to read information about users bit by bit. Despite the vulnerability, it was not possible for attackers to get password hashes.
The vulnerability has been labelled CVE-2023-28853, with a risk assessment of “high”. Mastodon versions from 2.5.0 were affected, but the developers have since closed the security gaps in versions 4.1.2, 4.0.4, and 3.5.8. The release notes for the three new Mastodon versions include a description of the vulnerability and version 3.0.6 of Ruby as a security update to address a previous ReDoS vulnerability.
Administrators of a Mastodon instance are advised to install the updated versions as soon as possible, as the developers classify the vulnerability that has been closed as high-risk. A few weeks ago, there was news that a configuration error in the Mastodon.social instance led to a data leak, albeit due to human error. During the expansion of hardware and software, an archive server was visible to all users for several weeks.
Overall, the Mastodon network has several vulnerabilities, but the developers are working to address them. Users should also take steps to secure their accounts wherever possible.