Grafana has released an emergency update to fix a zero-day vulnerability that is being tracked as CVE-2021-43798.
While this addition to previous patches was released to fix the issue, it became necessary after exploits were circulated over Twitter.
Since Proof-of-concept on how to exploit the vulnerability was publicly available Grafana was forced to release a fix. CEV-2021-43798 received a severity of 7.5 and can still be exploited on on-premise servers that have yet to be updated.
CEV-2021-43798 is described as a path traversal flaw that could allow attackers to navigate outside the Grafana folder and go ahead to remotely access restricted locations on the server.
In its explanation, Grafana explained that the root cause of the problem lies in the URL provided for installed plug-ins. According to Grafana, the URL was vulnerable to path traversal attacks. Currently, thousands of Grafana servers are exposed to this attack. Those who cannot install the update should ensure that their servers are not accessible from the public web.