Pi-hole is a DNS sinkhole that protects devices from unwanted content without installing any client-side software. Prior to 6.5, gravity.sh checks file:// adlist readability with sudo -u pihole test -r but then allows curl, sometimes running as root, to normalize URL dot segments and open a different file. A pihole-readable decoy can therefore pass the check while curl reads a root-only target, and /proc/self paths can similarly resolve against different processes.
Exploitation requires an administrator who can add adlists and can place a symlink and decoy on the filesystem. This issue is fixed in version 6.5.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
High
Admin privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/pi-hole/pi-hole/commit/14554737be53c392abffc69677f6b9df02ae7…
security-advisories@github.com
https://github.com/pi-hole/pi-hole/pull/6719
security-advisories@github.com
https://github.com/pi-hole/pi-hole/releases/tag/v6.5
security-advisories@github.com
https://github.com/pi-hole/pi-hole/security/advisories/GHSA-g63w-24cr-p3w6
security-advisories@github.com