Prometheus Exporter-Toolkit is vulnerable to authentication bypass
Moderate severity
GitHub Reviewed
Published
Nov 29, 2022
in
prometheus/exporter-toolkit
•
Updated Jan 23, 2024
Package
Affected versions
>= 0.8.0, < 0.8.2
< 0.7.2
Patched versions
0.8.2
0.7.2
Description
Published by the National Vulnerability Database
Nov 29, 2022
Published to the GitHub Advisory Database
Dec 2, 2022
Reviewed
Dec 2, 2022
Last updated
Jan 23, 2024
Impact
Prometheus and its exporters can be secured by a web.yml file that specifies usernames and hashed passwords for basic authentication.
Passwords are hashed with bcrypt, which means that even if you have access to the hash, it is very hard to find the original password back.
However, a flaw in the way this mechanism was implemented in the exporter toolkit makes it possible with people who know the hashed password to authenticate against Prometheus.
A request can be forged by an attacker to poison the internal cache used to cache the computation of hashes and make subsequent requests successful. This cache is used in both happy and unhappy scenarios in order to limit side channel attacks that could tell an attacker if a user is present in the file or not.
Patches
The exporter-toolkit v0.7.3 and v0.8.2 have been released to address this issue.
Workarounds
There is no workaround but attacker must have access to the hashed password, stored in disk, to bypass the authentication.
Credit
We want to thank Lei Wan reporting this security issue.
References