This security advisory describes one medium risk vulnerability.
1) Permissions, Privileges, and Access Controls
The vulnerability allows a remote attacker to gain unauthorized access to projects.
The vulnerability exists due to incorrect membership handling of group sharing feature. Sharing a group with another group could grant project access to unauthorized users.
Install updates from vendor’s website.
Vulnerable software versions
Gitlab Community Edition:
12.5.0, 12.5.1, 12.5.2, 12.5.3, 12.5.4, 12.5.5, 12.5.6, 12.5.7, 12.5.9, 12.6.0, 12.6.1, 12.6.2, 12.6.3, 12.6.4, 12.6.6, 12.7.0, 12.7.1, 12.7.2, 12.7.4, 12.7.5
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.