CVE-2020-35591 Auth bypass in n/a
Attackers can hijack user sessions by injecting cookies before login, gaining unauthorized access to Pi-hole admin accounts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2020-35591?
CVE-2020-35591 is a medium-severity authentication bypass vulnerability in n/a, published on 18 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Pi-hole 5.0, 5.1, and 5.1.1 allows Session Fixation. The application does not generate a new session cookie after the user is logged in. A malicious user is able to create a new session cookie value and inject it to a victim. After the victim logs in, the injected cookie becomes valid, giving the attacker access to the user's account through the active session.
Weakness: CWE-384
Which versions are affected by CVE-2020-35591?
It affects 1 product.
Products include Pi-Hole Pi-Hole.
How do I fix CVE-2020-35591?
No fix has been published for CVE-2020-35591 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2020-35591 being exploited?
There is no known exploitation of CVE-2020-35591 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2020-8816 Pi-Hole AdminLTE Remote Code Execution
- CVE-2025-34087 Pi-Hole AdminLTE Whitelist (now 'Web Allowlist') Remote Command Execution
- CVE-2026-50130 Pi-hole: Local privilege escalation from `pihole` user to root via `/etc/pihole/logrotate`
- CVE-2020-11108 File upload in n/a
- CVE-2019-13051 Pi-Hole 4.3 allows Command Injection.
Sources
Also known as GHSA-fg2g-p9qq-jw38.